Form of Certification required from Principal Executive Officer and Principal Financial Officer in connection with each Form N

Report of Independent Registered Public Accounting Firm

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Other third-party marks appearing herein are the property of their respective owners.

This report and the financial statements contained herein are submitted for the general information of the shareholders of the Fund. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by an effective prospectus.

A fund files its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-PORT. Forms N-PORT are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-PORT may be reviewed and copied at the SEC's Public Reference Room in Washington, DC. Information regarding the operation of the SEC's Public Reference Room may be obtained by calling 1-800-SEC-0330.

For a complete list of a fund's portfolio holdings, view the most recent holdings listing, semiannual report, or annual report on Fidelity's web site at http://www.fidelity.com, http://www.institutional.fidelity.com, or http://www.401k.com, as applicable.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Fund nor Fidelity Distributors Corporation is a bank.

Investment Summary/Performance April 30, 2023 (Unaudited)

Current 7-Day Yields

Fidelity® Money Market Fund	4.56%
Premium Class	4.68%

Yield refers to the income paid by the Fund over a given period. Yield for money market funds is usually for seven-day periods, as it is here, though it is expressed as an annual percentage rate. Past performance is no guarantee of future results. Yield will vary and it's possible to lose money investing in the Fund.

Effective Maturity Diversification (% of Fund's Investments)
Days
1 - 7	81.2
8 - 30	5.7
31 - 60	4.3
61 - 90	3.6
91 - 180	5.2
Effective maturity is determined in accordance with the requirements of Rule 2a-7 under the Investment Company Act of 1940.

Asset Allocation (% of Fund's net assets)

Percentages shown as 0.0% may reflect amounts less than 0.05%.

Showing Percentage of Net Assets

Certificate of Deposit - 11.2%
	Yield (%)(a)	Principal Amount (b) (000s)	Value ($) (000s)
Domestic Certificates Of Deposit - 0.5%
Bank of America NA
7/11/23 to 8/31/23 (c)	5.12 to 5.14	399,000	399,000

New York Branch, Yankee Dollar, Foreign Banks - 10.7%
Bayerische Landesbank
5/30/23 to 5/31/23	5.20 to 5.20	856,000	856,000
BNP Paribas Fortis
7/31/23	5.37	208,000	208,000
Canadian Imperial Bank of Commerce
10/17/23 to 10/18/23	5.47 to 5.47	430,000	430,000
Credit Agricole CIB
5/2/23 to 8/18/23 (c)	4.82 to 5.43	2,522,700	2,522,701
Landesbank Baden-Wuerttemberg New York Branch
5/2/23	4.88	214,000	214,000
Mitsubishi UFJ Trust & Banking Corp.
5/4/23 to 5/5/23	4.82 to 4.82	721,000	721,000
Mizuho Corporate Bank Ltd.
5/5/23 to 5/12/23	4.81 to 4.85	1,638,000	1,638,000
MUFG Bank Ltd.
7/6/23 to 7/12/23 (c)(d)	5.11 to 5.11	562,000	562,000
Sumitomo Mitsui Trust Bank Ltd.
5/8/23 to 6/23/23	4.82 to 5.17	1,338,200	1,338,200
TOTAL NEW YORK BRANCH, YANKEE DOLLAR, FOREIGN BANKS			8,489,901
TOTAL CERTIFICATE OF DEPOSIT (Cost $8,888,901)			8,888,901

Financial Company Commercial Paper - 16.8%
	Yield (%)(a)	Principal Amount (b) (000s)	Value ($) (000s)
Bank of Montreal
5/2/23 to 9/5/23 (c)	5.16 to 5.51	1,204,000	1,196,764
Bank of Nova Scotia
5/1/23 to 7/17/23 (c)	5.13 to 5.51	1,087,000	1,085,042
Barclays Bank PLC/Barclays U.S. CCP Funding LLC
5/5/23 to 6/1/23 (e)	4.84 to 5.02	307,000	306,344
Bayerische Landesbank
5/3/23 to 5/4/23	5.06 to 5.06	428,000	427,850
BNP Paribas SA
7/31/23	5.36	209,250	206,457
BofA Securities, Inc.
5/3/23 to 8/7/23 (c)(d)	5.19 to 5.51	567,000	567,000
BPCE SA
7/17/23 to 8/7/23	5.30 to 5.40	1,907,250	1,883,542
Credit Agricole CIB
5/3/23	4.84	146,000	145,961
Federation des caisses Desjardin
7/19/23	5.04	125,000	123,650
J.P. Morgan Securities, LLC
5/10/23 to 5/24/23 (c)(d)	5.38 to 5.38	369,000	369,000
Landesbank Baden-Wurttemberg
5/1/23	4.85	1,931,000	1,931,000
Lloyds Bank PLC
5/11/23 to 5/12/23	4.92 to 4.92	164,000	163,768
Mizuho Bank Ltd. Singapore Branch
5/8/23 to 6/9/23	4.85 to 5.04	571,000	569,198
National Bank of Canada
5/25/23	5.26	407,000	405,611
NatWest Markets PLC
5/2/23 to 5/5/23	4.83 to 4.86	429,000	428,855
Sumitomo Mitsui Trust Bank Ltd.
5/22/23 to 6/21/23	4.92 to 5.15	1,180,000	1,173,611
Svenska Handelsbanken AB
9/1/23 to 9/5/23 (c)	5.05 to 5.32	614,000	606,744
Svenska Handelsbanken, Inc.
7/24/23 (c)(d)	5.20	202,000	202,000
The Toronto-Dominion Bank
5/22/23 to 10/17/23	5.18 to 5.38	1,349,000	1,328,996
Toyota Motor Credit Corp.
8/30/23	5.33	81,000	79,587
UBS AG London Branch
5/23/23	5.45	122,000	121,605
TOTAL FINANCIAL COMPANY COMMERCIAL PAPER (Cost $13,322,585)			13,322,585

Asset Backed Commercial Paper - 0.7%
	Yield (%)(a)	Principal Amount (b) (000s)	Value ($) (000s)
Gotham Funding Corp. (Liquidity Facility Bank of Tokyo-Mitsubishi UFJ Ltd.)

5/1/23	0.48	206,000	206,000
7/10/23	0.53	128,000	126,706
7/11/23	0.53	113,000	111,841
7/17/23	0.53	96,000	94,926
TOTAL ASSET BACKED COMMERCIAL PAPER (Cost $539,473)			539,473

Variable Rate Demand Note - 0.0%
	Yield (%)(a)	Principal Amount (b) (000s)	Value ($) (000s)
Florida - 0.0%
Florida Timber Fin. III LLC Taxable Series 2008, LOC Wells Fargo Bank NA, VRDN
5/5/23 (c)	5.02	40,000	40,000

TOTAL VARIABLE RATE DEMAND NOTE (Cost $40,000)			40,000

U.S. Government Agency Debt - 0.1%
	Yield (%)(a)	Principal Amount (b) (000s)	Value ($) (000s)
Federal Agencies - 0.1%
Federal Home Loan Bank
9/19/23	5.11	94,000	92,167

TOTAL U.S. GOVERNMENT AGENCY DEBT (Cost $92,167)			92,167

Non-Negotiable Time Deposit - 1.6%
	Yield (%)(a)	Principal Amount (b) (000s)	Value ($) (000s)
Time Deposits - 1.6%
Landesbank Hessen-Thuringen London Branch
5/2/23 to 5/4/23	4.84 to 4.87	1,285,000	1,285,000

TOTAL NON-NEGOTIABLE TIME DEPOSIT (Cost $1,285,000)			1,285,000

U.S. Government Agency Repurchase Agreement - 11.5%
	Maturity Amount ($) (000s)	Value ($) (000s)
In a joint trading account at 4.81% dated 4/28/23 due 5/1/23 (Collateralized by U.S. Government Obligations) #	4,090,739	4,089,100
With:
ABN AMRO Bank NV at 4.81%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $179,591,980, 2.00% - 5.50%, 1/31/24 - 12/20/52)	176,071	176,000
BMO Harris Bank NA at 4.81%, dated:
3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $97,404,930, 2.50% - 6.50%, 7/20/41 - 1/20/63)	95,533	95,000
4/12/23 due 5/3/23 (Collateralized by U.S. Government Obligations valued at $85,897,508, 3.00% - 5.00%, 7/20/41 - 4/20/52)	84,236	84,000
BNP Paribas, SA at:
4.81%, dated 4/20/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $734,725,273, 0.00% - 6.00%, 7/31/24 - 4/20/53)	720,344	719,000
4.82%, dated 4/4/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $95,311,340, 0.00% - 6.00%, 7/15/23 - 4/20/53)	93,374	93,000
BofA Securities, Inc. at 4.82%, dated:
4/18/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $120,569,167, 1.75%, 1/31/29) (c)(d)(f)	118,253	118,000
4/26/23 due 5/5/23 (Collateralized by U.S. Treasury Obligations valued at $96,964,823, 3.00%, 7/31/24) (c)(d)(f)	95,382	95,000
CIBC Bank U.S.A. at 4.81%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $251,298,573, 0.63% - 8.00%, 6/1/25 - 5/1/53)	246,375	245,000
Citibank NA at 4.81%, dated 4/27/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $146,915,283, 0.00% - 8.88%, 8/17/23 - 9/15/65)	143,134	143,000
Citigroup Global Capital Markets, Inc. at 4.81%, dated:
3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $145,594,770, 1.38% - 7.50%, 6/30/23 - 3/20/53)	142,797	142,000
4/27/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $170,431,088, 1.88% - 6.50%, 6/30/26 - 4/20/53)	167,156	167,000
Goldman Sachs & Co. at 4.81%, dated:
4/24/23 due 5/1/23 (Collateralized by U.S. Government Obligations valued at $437,989,260, 0.00% - 7.00%, 6/8/23 - 1/1/58)	429,401	429,000
4/25/23 due 5/2/23 (Collateralized by U.S. Government Obligations valued at $291,953,862, 1.50% - 6.50%, 2/1/27 - 1/15/58)	286,267	286,000
4/26/23 due 5/3/23 (Collateralized by U.S. Government Obligations valued at $583,829,770, 2.50% - 6.50%, 5/1/37 - 8/15/57)	572,535	572,000
4/27/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $194,924,121, 1.50% - 7.50%, 9/1/24 - 4/1/53)	191,179	191,000
4/28/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $194,898,091, 1.50% - 6.50%, 7/31/24 - 5/1/53)	191,153	191,000
RBC Dominion Securities at 4.81%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $465,493,041, 0.00% - 5.50%, 1/15/26 - 1/20/53)	456,548	454,000
RBC Financial Group at 4.81%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $877,728,067, 0.00% - 7.50%, 7/20/23 - 5/1/53)	859,798	855,000
TOTAL U.S. GOVERNMENT AGENCY REPURCHASE AGREEMENT (Cost $9,144,100)		9,144,100

U.S. Treasury Repurchase Agreement - 54.8%
	Maturity Amount ($) (000s)	Value ($) (000s)
With:
Credit AG at 4.81%, dated 4/20/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $86,827,490, 2.88%, 6/15/25)	85,159	85,000
Federal Reserve Bank of New York at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $43,393,350,408, 12.50% - 2.88%, 8/15/23 - 3/31/27)	43,393,350	43,376,000
MUFG Securities (Canada), Ltd. at 4.81%, dated 4/24/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $43,901,041, 0.00% - 6.13%, 8/15/23 - 2/15/50)	43,057	43,000
TOTAL U.S. TREASURY REPURCHASE AGREEMENT (Cost $43,504,000)		43,504,000

Other Repurchase Agreement - 3.1%
	Maturity Amount ($) (000s)	Value ($) (000s)
Other Repurchase Agreement - 3.1%
With:
BMO Capital Markets Corp. at:
4.95%, dated 4/28/23 due 5/1/23 (Collateralized by Corporate Obligations valued at $93,488,838, 2.85% - 5.87%, 9/10/24 - 6/1/77)	89,037	89,000
5.01%, dated 4/28/23 due 5/1/23 (Collateralized by Corporate Obligations valued at $94,356,131, 2.53% - 13.38%, 5/30/24 - 6/1/50)	89,037	89,000
BMO Chicago Branch at 5.01%, dated 4/28/23 due 5/1/23 (Collateralized by Corporate Obligations valued at $11,555,421, 0.00% - 7.00%, 5/15/23 - 2/1/53)	11,005	11,000
BNP Paribas Prime Brokerage, Inc. at:
5.06%, dated 4/28/23 due 5/1/23 (Collateralized by Equity Securities valued at $142,620,113)	132,056	132,000
5.07%, dated 4/27/23 due 5/4/23 (Collateralized by Equity Securities valued at $189,106,527) (c)(d)(f)	175,173	175,000
5.26%, dated 3/29/23 due 5/30/23 (Collateralized by Corporate Obligations valued at $329,676,963, 0.00% - 7.50%, 7/1/23 - 8/15/52) (c)(d)(f)	306,754	304,000
HSBC Securities, Inc. at 5.04%, dated 4/28/23 due 5/1/23 (Collateralized by Corporate Obligations valued at $22,690,369, 4.00% - 7.35%, 7/23/25 - 4/1/63)	21,009	21,000
ING Financial Markets LLC at 5.05%, dated 4/28/23 due 5/1/23 (Collateralized by Equity Securities valued at $129,654,548)	120,051	120,000
J.P. Morgan Securities, LLC at 5.38%, dated 4/27/23 due 7/27/23 (Collateralized by Corporate Obligations valued at $733,462,688, 0.00% - 7.50%, 6/1/23 - 12/1/59) (c)(d)(f)	691,177	679,000
Mitsubishi UFJ Securities (U.S.A.), Inc. at:
5.04%, dated 4/28/23 due 5/1/23 (Collateralized by Equity Securities valued at $59,424,985)	55,023	55,000
5.33%, dated 4/28/23 due 5/1/23 (Collateralized by Equity Securities valued at $8,643,886)	8,004	8,000
Mizuho Securities U.S.A., Inc. at:
5.08%, dated 4/28/23 due 5/1/23 (Collateralized by Equity Securities valued at $85,356,119)	79,033	79,000
5.31%, dated:
4/10/23 due 6/9/23 (Collateralized by Corporate Obligations valued at $184,672,977, 2.51% - 13.25%, 9/18/23 - 6/5/2115) (c)(d)(f)	175,540	174,000
4/27/23 due 6/26/23 (Collateralized by Mortgage Loan Obligations valued at $97,168,302, 0.00% - 12.17%, 7/15/30 - 8/25/52) (c)(d)(f)	88,779	88,000
RBC Capital Markets Co. at 5.31%, dated 4/28/23 due 6/27/23 (Collateralized by Corporate Obligations valued at $92,635,417, 2.56% - 9.75%, 2/15/27 - 6/15/39) (c)(d)(f)	88,779	88,000
RBS Securities, Inc. at 5.07%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $45,364,700, 0.00% - 5.39%, 1/22/24 - 4/25/34)	44,019	44,000
Truist Securities, Inc. at 5.1%, dated 4/28/23 due 5/1/23 (Collateralized by Municipal Bond Obligations valued at $81,570,705, 0.00% - 6.50%, 7/1/27 - 10/1/53)	77,033	77,000
Wells Fargo Securities, LLC at:
4.97%, dated 4/28/23 due 5/1/23 (Collateralized by Commercial Paper valued at $158,685,696, 5/3/23 - 9/19/23)	154,064	154,000
5.4%, dated 2/3/23 due 5/4/23 (Collateralized by Commercial Paper valued at $65,843,407, 5/11/23 - 10/10/23)	63,851	63,000
5.82%, dated 4/26/23 due 7/24/23 (Collateralized by Corporate Obligations valued at $47,514,297, 0.00% - 6.50%, 10/15/23 - 2/15/30)	44,633	44,000
TOTAL OTHER REPURCHASE AGREEMENT (Cost $2,494,000)		2,494,000

TOTAL INVESTMENT IN SECURITIES - 99.8% (Cost $79,310,226)	79,310,226
NET OTHER ASSETS (LIABILITIES) - 0.2%	131,822
NET ASSETS - 100.0%	79,442,048

Security Type Abbreviations

VRDN

VARIABLE RATE DEMAND NOTE (A debt instrument that is payable upon demand, either daily, weekly or monthly)

The date shown for securities represents the date when principal payments must be paid, taking into account any call options exercised by the issuer and any permissible maturity shortening features other than interest rate resets.

Any values shown as $0 in the Schedule of Investments may reflect amounts less than $500.

Legend

(a)	Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b)	Amount is stated in United States dollars unless otherwise noted.

(c)	Coupon rates for floating and adjustable rate securities reflect the rates in effect at period end.

(d)	Coupon is indexed to a floating interest rate which may be multiplied by a specified factor and/or subject to caps or floors.

(e)

Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these securities amounted to $306,344,000 or 0.4% of net assets.

(f)	The maturity amount is based on the rate at period end.

Investment Valuation

All investments are categorized as Level 2 under the Fair Value Hierarchy. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in these securities. For more information on valuation inputs, refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

Other Information
# Additional information on each counterparty to the repurchase agreement is as follows:
Repurchase Agreement / Counterparty	Value ($) (000's)
$4,089,100,000 due 5/01/23 at 4.81%
BNY Mellon Capital Markets LLC	119,268
Bank of America, N.A.	344,557
BofA Securities, Inc.	245,290
Citigroup Global Markets, Inc.	239,276
HSBC Securities (USA), Inc.	43,075
JP Morgan Securities LLC	95,722
Mitsubishi UFJ Securities Holdings Ltd	95,722
Mizuho Securities USA, Inc.	33,503
Nomura Securities International	293,454
RBC Dominion Securities, Inc.	287,131
Sumitomo Mitsui Banking Corp.	1,387,805
Sumitomo Mitsui Banking Corp. NY	330,035
Wells Fargo Securities LLC	574,262
	4,089,100

Statement of Assets and Liabilities
Amounts in thousands (except per-share amounts)				April 30, 2023

Assets
Investment in securities, at value (including repurchase agreements of $55,142,100) - See accompanying schedule Unaffiliated issuers (cost $79,310,226):			$	79,310,226
Cash				1,000
Receivable for fund shares sold				374,566
Interest receivable				107,562
Receivable for interfund loans				7,002
Prepaid expenses				12
Receivable from investment adviser for expense reductions				3,633
Other affiliated receivables				1
Other receivables				346
Total assets				79,804,348
Liabilities
Payable for fund shares redeemed	$	286,922
Distributions payable		48,926
Accrued management fee		16,317
Other affiliated payables		7,113
Other payables and accrued expenses		3,022
Total Liabilities				362,300
Net Assets			$	79,442,048
Net Assets consist of:
Paid in capital			$	79,441,885
Total accumulated earnings (loss)				163
Net Assets			$	79,442,048

Net Asset Value and Maximum Offering Price
Fidelity Money Market Fund :
Net Asset Value , offering price and redemption price per share ($8,226,176 ÷ 8,225,511 shares)			$	1.00
Premium Class :
Net Asset Value , offering price and redemption price per share ($71,215,872 ÷ 71,213,456 shares)			$	1.00

Statement of Operations
Amounts in thousands				Year ended April 30, 2023
Investment Income
Interest (including $1,134 from affiliated interfund lending)			$	2,001,571
Expenses
Management fee	$	134,585
Transfer agent fees		57,003
Accounting fees and expenses		1,982
Custodian fees and expenses		322
Independent trustees' fees and expenses		173
Registration fees		4,605
Audit		48
Legal		28
Miscellaneous		95
Total expenses before reductions		198,841
Expense reductions		(30,896)
Total expenses after reductions				167,945
Net Investment income (loss)				1,833,626
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment Securities:
Unaffiliated issuers		5
Total net realized gain (loss)				5
Net increase in net assets resulting from operations			$	1,833,631

Statement of Changes in Net Assets

Amount in thousands		Year ended April 30, 2023		Year ended April 30, 2022
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$	1,833,626	$	7,511
Net realized gain (loss)		5		91
Net increase in net assets resulting from operations		1,833,631		7,602
Distributions to shareholders		(1,833,654)		(7,509)
Share transactions - net increase (decrease)		48,063,691		(8,111,841)
Total increase (decrease) in net assets		48,063,668		(8,111,748)

Net Assets
Beginning of period		31,378,380		39,490,128
End of period	$	79,442,048	$	31,378,380

Financial Highlights

Fidelity® Money Market Fund

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.029		- B		- B		.016		.020
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.029		- B		- B		.016		.020
Distributions from net investment income		(.029)		- B		- B		(.016)		(.020)
Total distributions		(.029)		- B		- B		(.016)		(.020)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		2.94%		.01%		.02%		1.61%		2.03%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.42%		.42%		.42%		.42%		.42%
Expenses net of fee waivers, if any		.42%		.18%		.25%		.42%		.42%
Expenses net of all reductions		.42%		.18%		.25%		.42%		.42%
Net investment income (loss)		3.31%		.01%		.03%		1.56%		2.06%
Supplemental Data
Net assets, end of period (in millions)	$	8,226	$	3,683	$	4,430	$	6,093	$	5,196

A Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

E Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.

Fidelity® Money Market Fund Premium Class

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.030		- B		- B		.017		.021
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.030		- B		- B		.017		.021
Distributions from net investment income		(.030)		- B		- B		(.017)		(.021)
Total distributions		(.030)		- B		- B		(.017)		(.021)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		3.07%		.02%		.05%		1.73%		2.16%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.36%		.36%		.36%		.36%		.37%
Expenses net of fee waivers, if any		.30%		.17%		.23%		.30%		.30%
Expenses net of all reductions		.30%		.17%		.23%		.30%		.30%
Net investment income (loss)		3.43%		.02% B		.05%		1.68%		2.18%
Supplemental Data
Net assets, end of period (in millions)	$	71,216	$	27,695	$	35,060	$	48,570	$	36,981

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

For the period ended April 30, 2023

( Amounts in thousands except percentages)

1. Organization.

Fidelity Money Market Fund (the Fund) is a fund of Fidelity Hereford Street Trust (the Trust) and is authorized to issue an unlimited number of shares. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Delaware statutory trust. The Fund offers Fidelity Money Market Fund and Premium Class shares, each of which has equal rights as to assets and voting privileges. Each class has exclusive voting rights with respect to matters that affect that class. Shares of the Fund are only available for purchase by retail shareholders.

2. Significant Accounting Policies.

The Fund is an investment company and applies the accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 Financial Services - Investment Companies . The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP), which require management to make certain estimates and assumptions at the date of the financial statements. Actual results could differ from those estimates. Subsequent events, if any, through the date that the financial statements were issued have been evaluated in the preparation of the financial statements. The Fund's Schedule of Investments lists any underlying mutual funds or exchange-traded funds (ETFs) but does not include the underlying holdings of these funds. The following summarizes the significant accounting policies of the Fund:

Investment Valuation. The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

As permitted by compliance with certain conditions under Rule 2a-7 of the 1940 Act, securities are valued at amortized cost, which approximates fair value. The amortized cost of an instrument is determined by valuing it at its original cost and thereafter amortizing any discount or premium from its face value at a constant rate until maturity. Securities held by a money market fund are generally high quality and liquid; however, they are reflected as Level 2 because the inputs used to determine fair value are not quoted prices in an active market.

Investment Transactions and Income. The net asset value per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time. Security transactions are accounted for as of trade date. Gains and losses on securities sold are determined on the basis of identified cost. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

Class Allocations and Expenses. Investment income, realized and unrealized capital gains and losses, common expenses of a fund, and certain fund-level expense reductions, if any, are allocated daily on a pro-rata basis to each class based on the relative net assets of each class to the total net assets of a fund. Each class differs with respect to transfer agent and distribution and service plan fees incurred, as applicable. Certain expense reductions may also differ by class, if applicable. For the reporting period, the allocated portion of income and expenses to each class as a percent of its average net assets may vary due to the timing of recording these transactions in relation to fluctuating net assets of the classes. Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expenses included in the accompanying financial statements reflect the expenses of that fund and do not include any expenses associated with any underlying mutual funds or exchange-traded funds. Although not included in a fund's expenses, a fund indirectly bears its proportionate share of these expenses through the net asset value of each underlying mutual fund or exchange-traded fund. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

Deferred Trustee Compensation. Under a Deferred Compensation Plan (the Plan) for certain Funds, certain independent Trustees have elected to defer receipt of a portion of their annual compensation. Deferred amounts are invested in affiliated mutual funds, are marked-to-market and remain in a fund until distributed in accordance with the Plan. The investment of deferred amounts and the offsetting payable to the Trustees presented below are included in the accompanying Statement of Assets and Liabilities in other receivables and other payables and accrued expenses, as applicable.

Fidelity Money Market Fund

$344

Income Tax Information and Distributions to Shareholders. Each year, the Fund intends to qualify as a regulated investment company under Subchapter M of the Internal Revenue Code, including distributing substantially all of its taxable income and realized gains. As a result, no provision for U.S. Federal income taxes is required. As of April 30, 2023, the Fund did not have any unrecognized tax benefits in the financial statements; nor is the Fund aware of any tax positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly change in the next twelve months. The Fund files a U.S. federal tax return, in addition to state and local tax returns as required. The Fund's federal income tax returns are subject to examination by the Internal Revenue Service (IRS) for a period of three fiscal years after they are filed. State and local tax returns may be subject to examination for an additional fiscal year depending on the jurisdiction.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are declared separately for each class. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP. In addition, the Fund claimed a portion of the payment made to redeeming shareholders as a distribution for income tax purposes. There were no significant book-to-tax differences during the period.

Capital accounts within the financial statements are adjusted for permanent book-tax differences. These adjustments have no impact on net assets or the results of operations. Capital accounts are not adjusted for temporary book-tax differences which will reverse in a subsequent period.

As of period end, the cost and unrealized appreciation (depreciation) in securities for federal income tax purposes were as follows:

Gross unrealized appreciation	$-
Gross unrealized depreciation	-
Net unrealized appreciation (depreciation)	$-
Tax Cost	$79,310,226

The tax-based components of distributable earnings as of period end were as follows:

Undistributed ordinary income

$163

The tax character of distributions paid was as follows:

	April 30, 2023	April 30, 2022
Ordinary Income	$1,833,654	$7,509

Repurchase Agreements. Pursuant to an Exemptive Order issued by the Securities and Exchange Commission, funds and other registered investment companies having management contracts with Fidelity Management and Research Company LLC, or its affiliates are permitted to transfer uninvested cash balances into joint trading accounts which are then invested in repurchase agreements. Funds may also invest directly with institutions in repurchase agreements. Upon settlement date, collateral is held in segregated accounts with custodian banks and may be obtained in the event of a default of the counterparty. The collateral balance is monitored on a daily basis to ensure it is at least equal to the principal amount of the repurchase agreement (including accrued interest). In the event of a default by the counterparty, realization of the collateral proceeds could be delayed, during which time the value of the collateral may decline.

Restricted Securities (including Private Placements). Funds may invest in securities that are subject to legal or contractual restrictions on resale. These securities generally may be resold in transactions exempt from registration or to the public if the securities are registered. Disposal of these securities may involve time-consuming negotiations and expense, and prompt sale at an acceptable price may be difficult. Information regarding restricted securities held at period end is included at the end of the Schedule of Investments, if applicable.

3. Fees and Other Transactions with Affiliates.

Management Fee and Expense Contract. Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund pays a monthly management fee that is based on an annual rate of .25% of the Fund's average net assets. Under the expense contract, total expenses of Fidelity Money Market Fund are limited to an annual rate of .42% of the class' average net assets, with certain exceptions.

Transfer Agent Fees. Fidelity Investments Institutional Operations Company LLC (FIIOC), an affiliate of the investment adviser, is the transfer, dividend disbursing and shareholder servicing agent for each class of the Fund. FIIOC receives asset-based fees with respect to each account. FIIOC pays for typesetting, printing and mailing of shareholder reports, except proxy statements. Premium Class pays a transfer agent fee equal to an annual rate of .10% of class-level average net assets.

Under the expense contract, Fidelity Money Market Fund will pay a portion of the transfer agent fee at an annual rate of up to .17% of class-level average net assets.

For the period, transfer agent fees for each class were as follows:

	Amount	% of Class-Level Average Net Assets
Fidelity Money Market Fund	$8,850	.16
Premium Class	48,153	.10
	$57,003

Accounting Fees. Fidelity Service Company, Inc. (FSC), an affiliate of the investment adviser, maintains the Fund's accounting records. The accounting fee is based on the level of average net assets for each month. For the period, the fees were equivalent to the following annual rates:

	% of Average Net Assets
Fidelity Money Market Fund	- A

A Amount represents less than .005%.

Interfund Lending Program. Pursuant to an Exemptive Order issued by the Securities and Exchange Commission (the SEC), the Fund, along with other registered investment companies having management contracts with Fidelity Management & Research Company LLC (FMR), or other affiliated entities of FMR, may participate in an interfund lending program. This program provides an alternative credit facility allowing the Fund to borrow from, or lend money to, other participating affiliated funds. Any open loans at period end are presented as Receivable for interfund loans in the Statement of Assets and Liabilities, and any accrued interest is included in Other affiliated receivables. Activity in this program during the period for which loans were outstanding was as follows:

		Average Loan Balance	Weighted Average Interest Rate
Fidelity Money Market Fund	Lender	21,870	3.33%

Interfund Trades. Funds may purchase from or sell securities to other Fidelity Funds under procedures adopted by the Board. The procedures have been designed to ensure these interfund trades are executed in accordance with Rule 17a-7 of the 1940 Act. During the period, there were no interfund trades.

4. Expense Reductions.

The investment adviser contractually agreed to reimburse Premium Class to the extent annual operating expenses exceeded .30% of the average net assets. This reimbursement will remain in place through August 31, 2024. Some expenses, for example the compensation of the independent Trustees, and certain other expenses such as interest expense, are excluded from this reimbursement. During the period, this reimbursement reduced Premium Class' expenses by $30,875.

Through arrangements with the Fund's custodian and each class' transfer agent, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses. During the period, custodian credits reduced the Fund's expenses by $21.

5. Distributions to Shareholders.

Distributions to shareholders of each class were as follows:

	Year ended April 30, 2023	Year ended April 30, 2022
Fidelity Money Market Fund
Distributions to shareholders
Fidelity Money Market Fund	$ 184,774	$466
Premium Class	1,648,880	7,043
Total	$1,833,654	$7,509

6. Share Transactions.

Share transactions for each class of shares at a $1.00 per share were as follows and may contain in-kind transactions, automatic conversions between classes or exchanges between affiliated funds:

	Shares	Shares	Dollars	Dollars
	Year ended April 30, 2023	Year ended April 30, 2022	Year ended April 30, 2023	Year ended April 30, 2022
Fidelity Money Market Fund
Fidelity Money Market Fund
Shares sold	10,688,040	1,328,747	$10,688,040	$1,328,747
Reinvestment of distributions	162,141	432	162,141	432
Shares redeemed	(6,307,429)	(2,076,499)	(6,307,429)	(2,076,499)
Net increase (decrease)	4,542,752	(747,320)	$4,542,752	$(747,320)
Premium Class
Shares sold	91,725,652	6,606,731	$91,725,652	$6,606,731
Reinvestment of distributions	1,413,717	6,493	1,413,717	6,493
Shares redeemed	(49,618,430)	(13,977,745)	(49,618,430)	(13,977,745)
Net increase (decrease)	43,520,939	(7,364,521)	$43,520,939	$(7,364,521)

7. Other.

A fund's organizational documents provide former and current trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the fund. In the normal course of business, a fund may also enter into contracts that provide general indemnifications. A fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against a fund. The risk of material loss from such claims is considered remote.

8. Risk and Uncertainties.

Many factors affect a fund's performance. Developments that disrupt global economies and financial markets, such as pandemics, epidemics, outbreaks of infectious diseases, war, terrorism, and environmental disasters, may significantly affect a fund's investment performance. The effects of these developments to a fund will be impacted by the types of securities in which a fund invests, the financial condition, industry, economic sector, and geographic location of an issuer, and a fund's level of investment in the securities of that issuer. Significant concentrations in security types, issuers, industries, sectors, and geographic locations may magnify the factors that affect a fund's performance.

Report of Independent Registered Public Accounting Firm

To the Board of Trustees of Fidelity Hereford Street Trust and Shareholders of Fidelity Money Market Fund

Opinion on the Financial Statements

We have audited the accompanying statement of assets and liabilities, including the schedule of investments, of Fidelity Money Market Fund (one of the funds constituting Fidelity Hereford Street Trust, referred to hereafter as the "Fund") as of April 30, 2023, the related statement of operations for the year ended April 30, 2023, the statement of changes in net assets for each of the two years in the period ended April 30, 2023, including the related notes, and the financial highlights for each of the five years in the period ended April 30, 2023 (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Fund as of April 30, 2023, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period ended April 30, 2023 and the financial highlights for each of the five years in the period ended April 30, 2023 in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Fund's management. Our responsibility is to express an opinion on the Fund's financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Fund in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits of these financial statements in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. Our procedures included confirmation of securities owned as of April 30, 2023 by correspondence with the custodians and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts

June 13, 2023

We have served as the auditor of one or more investment companies in the Fidelity group of funds since 1932.

TRUSTEES AND OFFICERS

The Trustees, Members of the Advisory Board (if any), and officers of the trust and fund, as applicable, are listed below. The Board of Trustees governs the fund and is responsible for protecting the interests of shareholders. The Trustees are experienced executives who meet periodically throughout the year to oversee the fund's activities, review contractual arrangements with companies that provide services to the fund, oversee management of the risks associated with such activities and contractual arrangements, and review the fund's performance. Each of the Trustees oversees 299 funds.

The Trustees hold office without limit in time except that (a) any Trustee may resign; (b) any Trustee may be removed by written instrument, signed by at least two-thirds of the number of Trustees prior to such removal; (c) any Trustee who requests to be retired or who has become incapacitated by illness or injury may be retired by written instrument signed by a majority of the other Trustees; and (d) any Trustee may be removed at any special meeting of shareholders by a two-thirds vote of the outstanding voting securities of the trust. Each Trustee who is not an interested person (as defined in the 1940 Act) of the trust and the fund is referred to herein as an Independent Trustee. Each Independent Trustee shall retire not later than the last day of the calendar year in which his or her 75th birthday occurs. The Independent Trustees may waive this mandatory retirement age policy with respect to individual Trustees. Officers and Advisory Board Members hold office without limit in time, except that any officer or Advisory Board Member may resign or may be removed by a vote of a majority of the Trustees at any regular meeting or any special meeting of the Trustees. Except as indicated, each individual has held the office shown or other offices in the same company for the past five years.

The fund's Statement of Additional Information (SAI) includes more information about the Trustees. To request a free copy, call Fidelity at 1-800-544-8544.

Experience, Skills, Attributes, and Qualifications of the Trustees. The Governance and Nominating Committee has adopted a statement of policy that describes the experience, qualifications, attributes, and skills that are necessary and desirable for potential Independent Trustee candidates (Statement of Policy). The Board believes that each Trustee satisfied at the time he or she was initially elected or appointed a Trustee, and continues to satisfy, the standards contemplated by the Statement of Policy. The Governance and Nominating Committee also engages professional search firms to help identify potential Independent Trustee candidates who have the experience, qualifications, attributes, and skills consistent with the Statement of Policy. From time to time, additional criteria based on the composition and skills of the current Independent Trustees, as well as experience or skills that may be appropriate in light of future changes to board composition, business conditions, and regulatory or other developments, have also been considered by the professional search firms and the Governance and Nominating Committee. In addition, the Board takes into account the Trustees' commitment and participation in Board and committee meetings, as well as their leadership of standing and ad hoc committees throughout their tenure.

In determining that a particular Trustee was and continues to be qualified to serve as a Trustee, the Board has considered a variety of criteria, none of which, in isolation, was controlling. The Board believes that, collectively, the Trustees have balanced and diverse experience, qualifications, attributes, and skills, which allow the Board to operate effectively in governing the fund and protecting the interests of shareholders. Information about the specific experience, skills, attributes, and qualifications of each Trustee, which in each case led to the Board's conclusion that the Trustee should serve (or continue to serve) as a trustee of the fund, is provided below.

Board Structure and Oversight Function. Abigail P. Johnson is an interested person and currently serves as Chairman. The Trustees have determined that an interested Chairman is appropriate and benefits shareholders because an interested Chairman has a personal and professional stake in the quality and continuity of services provided to the fund. Independent Trustees exercise their informed business judgment to appoint an individual of their choosing to serve as Chairman, regardless of whether the Trustee happens to be independent or a member of management. The Independent Trustees have determined that they can act independently and effectively without having an Independent Trustee serve as Chairman and that a key structural component for assuring that they are in a position to do so is for the Independent Trustees to constitute a substantial majority for the Board. The Independent Trustees also regularly meet in executive session. Michael E. Kenneally serves as Chairman of the Independent Trustees and as such (i) acts as a liaison between the Independent Trustees and management with respect to matters important to the Independent Trustees and (ii) with management prepares agendas for Board meetings.

Fidelity ® funds are overseen by different Boards of Trustees. The fund's Board oversees Fidelity's investment-grade bond, money market, asset allocation and certain equity funds, and other Boards oversee Fidelity's alternative investment, high income and other equity funds. The asset allocation funds may invest in Fidelity ® funds that are overseen by such other Boards. The use of separate Boards, each with its own committee structure, allows the Trustees of each group of Fidelity ® funds to focus on the unique issues of the funds they oversee, including common research, investment, and operational issues. On occasion, the separate Boards establish joint committees to address issues of overlapping consequences for the Fidelity ® funds overseen by each Board.

The Trustees operate using a system of committees to facilitate the timely and efficient consideration of all matters of importance to the Trustees, the fund, and fund shareholders and to facilitate compliance with legal and regulatory requirements and oversight of the fund's activities and associated risks. The Board, acting through its committees, has charged FMR and its affiliates with (i) identifying events or circumstances the occurrence of which could have demonstrably adverse effects on the fund's business and/or reputation; (ii) implementing processes and controls to lessen the possibility that such events or circumstances occur or to mitigate the effects of such events or circumstances if they do occur; and (iii) creating and maintaining a system designed to evaluate continuously business and market conditions in order to facilitate the identification and implementation processes described in (i) and (ii) above. Because the day-to-day operations and activities of the fund are carried out by or through FMR, its affiliates, and other service providers, the fund's exposure to risks is mitigated but not eliminated by the processes overseen by the Trustees. While each of the Board's committees has responsibility for overseeing different aspects of the fund's activities, oversight is exercised primarily through the Operations and Audit Committees. In addition, an ad hoc Board committee of Independent Trustees has worked with FMR to enhance the Board's oversight of investment and financial risks, legal and regulatory risks, technology risks, and operational risks, including the development of additional risk reporting to the Board. The Operations Committee also worked and continues to work with FMR to enhance the stress tests required under SEC regulations for money market funds. Appropriate personnel, including but not limited to the fund's Chief Compliance Officer (CCO), FMR's internal auditor, the independent accountants, the fund's Treasurer and portfolio management personnel, make periodic reports to the Board's committees, as appropriate, including an annual review of Fidelity's risk management program for the Fidelity ® funds. The responsibilities of each standing committee, including their oversight responsibilities, are described further under "Standing Committees of the Trustees."

Interested Trustees*:

Correspondence intended for a Trustee who is an interested person may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Abigail P. Johnson (1961)

Year of Election or Appointment: 2009

Trustee

Chairman of the Board of Trustees

Ms. Johnson also serves as Trustee of other Fidelity ® funds. Ms. Johnson serves as Chairman (2016-present), Chief Executive Officer (2014-present), and Director (2007-present) of FMR LLC (diversified financial services company), President of Fidelity Financial Services (2012-present) and President of Personal, Workplace and Institutional Services (2005-present). Ms. Johnson is Chairman and Director of Fidelity Management & Research Company LLC (investment adviser firm, 2011-present). Previously, Ms. Johnson served as Chairman and Director of FMR Co., Inc. (investment adviser firm, 2011-2019), Vice Chairman (2007-2016) and President (2013-2016) of FMR LLC, President and a Director of Fidelity Management & Research Company (2001-2005), a Trustee of other investment companies advised by Fidelity Management & Research Company, Fidelity Investments Money Management, Inc. (investment adviser firm), and FMR Co., Inc. (2001-2005), Senior Vice President of the Fidelity ® funds (2001-2005), and managed a number of Fidelity ® funds. Ms. Abigail P. Johnson and Mr. Arthur E. Johnson are not related.

Jennifer Toolin McAuliffe (1959)

Year of Election or Appointment: 2016

Trustee

Ms. McAuliffe also serves as Trustee of other Fidelity ® funds and as Trustee of Fidelity Charitable (2020-present). Previously, Ms. McAuliffe served as Co-Head of Fixed Income of Fidelity Investments Limited (now known as FIL Limited (FIL)) (diversified financial services company), Director of Research for FIL's credit and quantitative teams in London, Hong Kong and Tokyo and Director of Research for taxable and municipal bonds at Fidelity Investments Money Management, Inc. Ms. McAuliffe previously served as a member of the Advisory Board of certain Fidelity ® funds (2016). Ms. McAuliffe was previously a lawyer at Ropes & Gray LLP and an international banker at Chemical Bank NA (now JPMorgan Chase & Co.). Ms. McAuliffe also currently serves as director or trustee of several not-for-profit entities.

* Determined to be an "Interested Trustee" by virtue of, among other things, his or her affiliation with the trust or various entities under common control with FMR.

+ The information includes the Trustee's principal occupation during the last five years and other information relating to the experience, attributes, and skills relevant to the Trustee's qualifications to serve as a Trustee, which led to the conclusion that the Trustee should serve as a Trustee for the fund.

Independent Trustees:

Correspondence intended for an Independent Trustee may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Elizabeth S. Acton (1951)

Year of Election or Appointment: 2013

Trustee

Ms. Acton also serves as Trustee of other Fidelity ® funds. Prior to her retirement, Ms. Acton served as Executive Vice President, Finance (2011-2012), Executive Vice President, Chief Financial Officer (2002-2011) and Treasurer (2004-2005) of Comerica Incorporated (financial services). Prior to joining Comerica, Ms. Acton held a variety of positions at Ford Motor Company (1983-2002), including Vice President and Treasurer (2000-2002) and Executive Vice President and Chief Financial Officer of Ford Motor Credit Company (1998-2000). Ms. Acton currently serves as a member of the Board and Audit and Finance Committees of Beazer Homes USA, Inc. (homebuilding, 2012-present). Ms. Acton previously served as a member of the Advisory Board of certain Fidelity ® funds (2013-2016).

Ann E. Dunwoody (1953)

Year of Election or Appointment: 2018

Trustee

General Dunwoody also serves as Trustee of other Fidelity ® funds. General Dunwoody (United States Army, Retired) was the first woman in U.S. military history to achieve the rank of four-star general and prior to her retirement in 2012 held a variety of positions within the U.S. Army, including Commanding General, U.S. Army Material Command (2008-2012). General Dunwoody currently serves as a member of the Board, Chair of Nomination Committee and a member of the Corporate Governance Committee of Kforce Inc. (professional staffing services, 2016-present) and a member of the Board of Automattic Inc. (software engineering, 2018-present). Previously, General Dunwoody served as President of First to Four LLC (leadership and mentoring services, 2012-2022), a member of the Advisory Board and Nominating and Corporate Governance Committee of L3 Technologies, Inc. (communication, electronic, sensor and aerospace systems, 2013-2019) and a member of the Board and Audit and Sustainability and Corporate Responsibility Committees of Republic Services, Inc. (waste collection, disposal and recycling, 2013-2016). General Dunwoody also serves on several boards for non-profit organizations, including as a member of the Board, Chair of the Nomination and Governance Committee and a member of the Audit Committee of the Noble Reach Foundation (formerly Logistics Management Institute) (consulting non-profit, 2012-present) and a member of the Board of ThanksUSA (military family education non-profit, 2014-present). Previously, General Dunwoody served as a member of the Board of Florida Institute of Technology (2015-2022) and a member of the Council of Trustees for the Association of the United States Army (advocacy non-profit, 2013-2021). General Dunwoody previously served as a member of the Advisory Board of certain Fidelity ® funds (2018).

John Engler (1948)

Year of Election or Appointment: 2014

Trustee

Mr. Engler also serves as Trustee of other Fidelity ® funds. Previously, Mr. Engler served as Governor of Michigan (1991-2003), President of the Business Roundtable (2011-2017) and interim President of Michigan State University (2018-2019). Previously, Mr. Engler served as a member of the Board of Stride, Inc. (formerly K12 Inc.) (technology-based education company, 2012-2022), a member of the Board of Universal Forest Products (manufacturer and distributor of wood and wood-alternative products, 2003-2019) and Trustee of The Munder Funds (2003-2014). Mr. Engler previously served as a member of the Advisory Board of certain Fidelity ® funds (2014-2016).

Robert F. Gartland (1951)

Year of Election or Appointment: 2010

Trustee

Mr. Gartland also serves as Trustee of other Fidelity ® funds. Prior to his retirement, Mr. Gartland held a variety of positions at Morgan Stanley (financial services, 1979-2007), including Managing Director (1987-2007) and Chase Manhattan Bank (1975-1978). Mr. Gartland previously served as Chairman and an investor in Gartland & Mellina Group Corp. (consulting, 2009-2019), as a member of the Board of National Securities Clearing Corporation (1993-1996) and as Chairman of TradeWeb (2003-2004).

Arthur E. Johnson (1947)

Year of Election or Appointment: 2008

Trustee

Mr. Johnson also serves as Trustee of other Fidelity ® funds. Prior to his retirement, Mr. Johnson served as Senior Vice President of Corporate Strategic Development of Lockheed Martin Corporation (defense contractor, 1999-2009). Mr. Johnson currently serves as a member of the Board of Booz Allen Hamilton (management consulting, 2011-present). Mr. Johnson previously served as a member of the Board of Eaton Corporation plc (diversified power management, 2009-2019) and a member of the Board of AGL Resources, Inc. (holding company, 2002-2016). Mr. Johnson previously served as Chairman (2018-2021) and Vice Chairman (2015-2018) of the Independent Trustees of certain Fidelity® funds. Mr. Arthur E. Johnson is not related to Ms. Abigail P. Johnson.

Michael E. Kenneally (1954)

Year of Election or Appointment: 2009

Trustee

Chairman of the Independent Trustees

Mr. Kenneally also serves as Trustee of other Fidelity ® funds and was Vice Chairman (2018-2021) of the Independent Trustees of certain Fidelity ® funds. Prior to retirement in 2005, he was Chairman and Global Chief Executive Officer of Credit Suisse Asset Management, the worldwide fund management and institutional investment business of Credit Suisse Group. Previously, Mr. Kenneally was an Executive Vice President and the Chief Investment Officer for Bank of America. In this role, he was responsible for the investment management, strategy and products delivered to the bank's institutional, high-net-worth and retail clients. Earlier, Mr. Kenneally directed the organization's equity and quantitative research groups. He began his career as a research analyst and then spent more than a dozen years as a portfolio manager for endowments, pension plans and mutual funds. He earned the Chartered Financial Analyst (CFA) designation in 1991.

Mark A. Murray (1954)

Year of Election or Appointment: 2016

Trustee

Mr. Murray also serves as Trustee of other Fidelity ® funds. Previously, Mr. Murray served as Co-Chief Executive Officer (2013-2016), President (2006-2013) and Vice Chairman (2013-2020) of Meijer, Inc. Mr. Murray serves as a member of the Board (2009-present) and Public Policy and Responsibility Committee (2009-present) and Chair of the Nuclear Review Committee (2019-present) of DTE Energy Company (diversified energy company). Mr. Murray previously served as a member of the Board of Spectrum Health (not-for-profit health system, 2015-2019) and as a member of the Board and Audit Committee and Chairman of the Nominating and Corporate Governance Committee of Universal Forest Products, Inc. (manufacturer and distributor of wood and wood-alternative products, 2004-2016). Mr. Murray also serves as a member of the Board of many community and professional organizations. Mr. Murray previously served as a member of the Advisory Board of certain Fidelity ® funds (2016).

Advisory Board Members and Officers:

Correspondence intended for a Member of the Advisory Board (if any) may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235. Correspondence intended for an officer may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210. Officers appear below in alphabetical order.

Name, Year of Birth; Principal Occupation

Laura M. Bishop (1961)

Year of Election or Appointment: 2022

Member of the Advisory Board

Ms. Bishop also serves as a Member of the Advisory Board of other funds. Prior to her retirement, Ms. Bishop held a variety of positions at United Services Automobile Association (2001-2020), including Executive Vice President and Chief Financial Officer (2014-2020) and Senior Vice President and Deputy Chief Financial Officer (2012-2014). Ms. Bishop currently serves as a member of the Audit Committee and Compensation and Personnel Committee (2021-present) of the Board of Directors of Korn Ferry (global organizational consulting).

Robert W. Helm (1957)

Year of Election or Appointment: 2021

Member of the Advisory Board

Mr. Helm also serves as a Member of the Advisory Board of other Fidelity ® funds. Mr. Helm was formerly Deputy Chairman (2003-2020), partner (1991-2020) and an associate (1984-1991) of Dechert LLP (formerly Dechert Price & Rhoads). Mr. Helm currently serves on boards and committees of several not-for-profit organizations, including as a Trustee and member of the Executive Committee of the Baltimore Council on Foreign Affairs, a member of the Board of Directors of the St. Vincent de Paul Society of Baltimore and a member of the Life Guard Society of Mt. Vernon.

Carol J. Zierhoffer (1960)

Year of Election or Appointment: 2023

Member of the Advisory Board

Ms. Zierhoffer also serves as a Member of the Advisory Board of other funds. Prior to her retirement, Ms. Zierhoffer held a variety of positions at Bechtel Corporation (engineering company, 2013-2019), including Principal Vice President and Chief Information Officer (2013-2016) and Senior Vice President and Chief Information Officer (2016-2019). Ms. Zierhoffer currently serves as a member of the Board of Directors, Audit Committee and Compensation Committee of Allscripts Healthcare Solutions, Inc. (healthcare technology, 2020-present) and as a member of the Board of Directors, Audit and Finance Committee and Nominating and Governance Committee of Atlas Air Worldwide Holdings, Inc. (aviation operating services, 2021-present). Previously, Ms. Zierhoffer served as a member of the Board of Directors and Audit Committee and as the founding Chair of the Information Technology Committee of MedAssets, Inc. (healthcare technology, 2013-2016).

Heather Bonner (1977)

Year of Election or Appointment: 2023

Assistant Treasurer

Ms. Bonner also serves as an officer of other funds. Ms. Bonner serves as Senior Vice President (2022-present), and is an employee of Fidelity Investments. Ms. Bonner serves as Assistant Treasurer of Fidelity CRET Trustee LLC (2022-present). Prior to joining Fidelity, Ms. Bonner served as Managing Director at AQR Capital Management (2013-2022) and was the Treasurer and Principal Financial Officer of the AQR Funds (2013-2022).

Craig S. Brown (1977)

Year of Election or Appointment: 2019

Assistant Treasurer

Mr. Brown also serves as an officer of other funds. Mr. Brown serves as Assistant Treasurer of FIMM, LLC (2021-present) and is an employee of Fidelity Investments (2013-present). Previously, Mr. Brown served as Assistant Treasurer of certain Fidelity ® funds (2019-2022).

John J. Burke III (1964)

Year of Election or Appointment: 2018

Chief Financial Officer

Mr. Burke also serves as Chief Financial Officer of other funds. Mr. Burke serves as Head of Investment Operations for Fidelity Fund and Investment Operations (2018-present) and is an employee of Fidelity Investments (1998-present). Previously Mr. Burke served as head of Asset Management Investment Operations (2012-2018).

Margaret Carey (1973)

Year of Election or Appointment: 2023

Secretary and Chief Legal Officer (CLO)

Ms. Carey also serves as an officer of other funds and as CLO of certain other Fidelity entities. She is a Senior Vice President and Deputy General Counsel of FMR LLC (diversified financial services company, 2019-present), and is an employee of Fidelity Investments.

David J. Carter (1973)

Year of Election or Appointment: 2020

Assistant Secretary

Mr. Carter also serves as Assistant Secretary of other funds. Mr. Carter serves as Senior Vice President, Deputy General Counsel (2022-present) and is an employee of Fidelity Investments (2005-present).

Jonathan Davis (1968)

Year of Election or Appointment: 2010

Assistant Treasurer

Mr. Davis also serves as an officer of other funds. Mr. Davis serves as Vice President Assistant Treasurer and is an employee of Fidelity Investments. Mr. Davis serves as Assistant Treasurer of certain Fidelity entities.

Laura M. Del Prato (1964)

Year of Election or Appointment: 2018

President and Treasurer

Ms. Del Prato also serves as an officer of other funds. Ms. Del Prato serves as Assistant Treasurer of FIMM, LLC (2021-present) and is an employee of Fidelity Investments (2017-present). Previously, Ms. Del Prato served as President and Treasurer of The North Carolina Capital Management Trust: Cash Portfolio and Term Portfolio (2018-2020). Prior to joining Fidelity Investments, Ms. Del Prato served as a Managing Director and Treasurer of the JPMorgan Mutual Funds (2014-2017). Prior to JPMorgan, Ms. Del Prato served as a partner at Cohen Fund Audit Services (accounting firm, 2012-2013) and KPMG LLP (accounting firm, 2004-2012).

Christopher M. Gouveia (1973)

Year of Election or Appointment: 2023

Chief Compliance Officer

Mr. Gouveia also serves as Chief Compliance Officer of other funds. Mr. Gouveia serves as Senior Vice President of Asset Management Compliance for Fidelity Investments and is an employee of Fidelity Investments. Previously, Mr. Gouveia served as Chief Compliance Officer of the North Carolina Capital Management Trust (2016-2019).

Colm A. Hogan (1973)

Year of Election or Appointment: 2016

Assistant Treasurer

Mr. Hogan also serves as an officer of other funds. Mr. Hogan serves as Assistant Treasurer of FIMM, LLC (2021-present) and FMR Capital, Inc. (2017-present) and is an employee of Fidelity Investments (2005-present). Previously, Mr. Hogan served as Deputy Treasurer of certain Fidelity ® funds (2016-2020) and Assistant Treasurer of certain Fidelity ® funds (2016-2018).

Chris Maher (1972)

Year of Election or Appointment: 2013

Assistant Treasurer

Mr. Maher also serves as an officer of other funds. Mr. Maher serves as Assistant Treasurer of FIMM, LLC (2021-present) and FMR Capital, Inc. (2017-present), and is an employee of Fidelity Investments (2008-present). Previously, Mr. Maher served as Assistant Treasurer of certain funds (2013-2020); Vice President of Asset Management Compliance (2013), Vice President of the Program Management Group of FMR (investment adviser firm, 2010-2013), and Vice President of Valuation Oversight (2008-2010).

Jamie Pagliocco (1964)

Year of Election or Appointment: 2020

Vice President

Mr. Pagliocco also serves as Vice President of other funds. Mr. Pagliocco serves as President of Fixed Income (2020-present), and is an employee of Fidelity Investments (2001-present). Previously, Mr. Pagliocco served as Co-Chief Investment Officer - Bond (2017-2020), Global Head of Bond Trading (2016-2019), and as a portfolio manager.

Brett Segaloff (1972)

Year of Election or Appointment: 2021

Anti-Money Laundering (AML) Officer

Mr. Segaloff also serves as an AML Officer of other funds and other related entities. He is Director, Anti-Money Laundering (2007-present) of FMR LLC (diversified financial services company) and is an employee of Fidelity Investments (1996-present).

Stacie M. Smith (1974)

Year of Election or Appointment: 2013

Assistant Treasurer

Ms. Smith also serves as an officer of other funds. Ms. Smith serves as Assistant Treasurer of FIMM, LLC (2021-present) and FMR Capital, Inc. (2017-present), is an employee of Fidelity Investments (2009-present), and has served in other fund officer roles. Prior to joining Fidelity Investments, Ms. Smith served as Senior Audit Manager of Ernst & Young LLP (accounting firm, 1996-2009). Previously, Ms. Smith served as Assistant Treasurer (2013-2019) and Deputy Treasurer (2013-2016) of certain Fidelity ® funds.

Jim Wegmann (1979)

Year of Election or Appointment: 2021

Deputy Treasurer

Mr. Wegmann also serves as an officer of other funds. Mr. Wegmann serves as Assistant Treasurer of FIMM, LLC (2021-present) and is an employee of Fidelity Investments (2011-present). Previously, Mr. Wegmann served as Assistant Treasurer of certain Fidelity ® funds (2019-2021).

Shareholder Expense Example

As a shareholder, you incur two types of costs: (1) transaction costs, which may include sales charges (loads) on purchase payments or redemption proceeds, as applicable and (2) ongoing costs, which generally include management fees, distribution and/or service (12b-1) fees and other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of investing in a fund and to compare these costs with the ongoing costs of investing in other mutual funds.

The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (November 1, 2022 to April 30, 2023).

Actual Expenses

The first line of the accompanying table provides information about actual account values and actual expenses. You may use the information in this line, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000.00 (for example, an $8,600 account value divided by $1,000.00 = 8.6), then multiply the result by the number in the first line for a class/Fund under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. If any fund is a shareholder of any underlying mutual funds or exchange-traded funds (ETFs) (the Underlying Funds), such fund indirectly bears its proportional share of the expenses of the Underlying Funds in addition to the direct expenses incurred presented in the table. These fees and expenses are not included in the annualized expense ratio used to calculate the expense estimate in the table below.

Hypothetical Example for Comparison Purposes

The second line of the accompanying table provides information about hypothetical account values and hypothetical expenses based on the actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds. If any fund is a shareholder of any Underlying Funds, such fund indirectly bears its proportional share of the expenses of the Underlying Funds in addition to the direct expenses as presented in the table. These fees and expenses are not included in the annualized expense ratio used to calculate the expense estimate in the table below.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transaction costs. Therefore, the second line of the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would have been higher.

	Annualized Expense Ratio- A	Beginning Account Value November 1, 2022	Ending Account Value April 30, 2023	Expenses Paid During Period- C November 1, 2022 to April 30, 2023
Fidelity® Money Market Fund
Fidelity® Money Market Fund	.42%
Actual		$ 1,000	$ 1,020.80	$ 2.10
Hypothetical- B		$ 1,000	$ 1,022.71	$ 2.11
Premium Class	.30%
Actual		$ 1,000	$ 1,021.40	$ 1.50
Hypothetical- B		$ 1,000	$ 1,023.31	$ 1.51

A Annualized expense ratio reflects expenses net of applicable fee waivers.

B 5% return per year before expenses

C Expenses are equal to the annualized expense ratio, multiplied by the average account value over the period, multiplied by 181/ 365 (to reflect the one-half year period). The fees and expenses of any Underlying Funds are not included in each annualized expense ratio.

Distributions (Unaudited)

The dividend and capital gains distributions for the fund(s) are available on Fidelity.com or Institutional.Fidelity.com.

A total of 0.23% of the dividends distributed during the fiscal year was derived from interest on U.S. Government securities which is generally exempt from state income tax.

The fund designates $561,595,464 of distributions paid in the calendar year 2022 as qualifying to be taxed as interest-related dividends for nonresident alien shareholders.

The fund designates $1,833,653,562 of distributions paid during the fiscal year ended 2023 as qualifying to be taxed as section 163(j) interest dividends.

The fund will notify shareholders in January 2024 of amounts for use in preparing 2023 income tax returns.

1.703534.125

SPM-ANN-0623

Fidelity® Government Money Market Fund

Annual Report

April 30, 2023

Contents

Report of Independent Registered Public Accounting Firm

You may also call 1-800-544-8544 if you're an individual investing directly with Fidelity, call 1-800-835-5092 if you're a plan sponsor or participant with Fidelity as your recordkeeper or call 1-877-208-0098 on institutional accounts or if you're an advisor or invest through one to request a free copy of the proxy voting guidelines.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Fund nor Fidelity Distributors Corporation is a bank.

Investment Summary/Performance April 30, 2023 (Unaudited)

Current 7-Day Yields

Capital Reserves Class	3.97%
Daily Money Class	4.22%
Advisor M Class	4.22%
Fidelity® Government Money Market Fund	4.50%
Class S	4.50%
Premium Class	4.60%
Class K6	4.67%

Yield refers to the income paid by the Fund over a given period. Yield for money market funds is usually for seven-day periods, as it is here, though it is expressed as an annual percentage rate. Past performance is no guarantee of future results. Yield will vary and it's possible to lose money investing in the Fund. A portion of the Fund's expenses was reimbursed and/or waived. Absent such reimbursements and/or waivers the yield for the period ending April 30, 2023, the most recent period shown in the table, would have been 2.88% for Advisor M Class, 4.19% for Premium Class, and 3.01% for Class K6.

Effective Maturity Diversification (% of Fund's Investments)
Days
1 - 7	92.6
8 - 30	0.4
31 - 60	0.9
61 - 90	0.7
91 - 180	0.9
> 180	4.5
Effective maturity is determined in accordance with the requirements of Rule 2a-7 under the Investment Company Act of 1940.

Asset Allocation (% of Fund's net assets)

Showing Percentage of Net Assets

U.S. Treasury Debt - 3.4%
	Yield (%)(a)	Principal Amount (b)	Value ($)
U.S. Treasury Obligations - 3.4%
U.S. Treasury Notes
10/31/23 to 10/31/24	5.06 to 5.27	8,928,600,000	8,925,962,544

TOTAL U.S. TREASURY DEBT (Cost $8,925,962,544)			8,925,962,544

U.S. Government Agency Debt - 29.3%
	Yield (%)(a)	Principal Amount (b)	Value ($)
Federal Agencies - 29.3%
Federal Farm Credit Bank
6/7/23 to 4/10/25 (c)	2.59 to 5.01	4,585,550,000	4,585,394,386
Federal Home Loan Bank
5/18/23 to 11/22/24 (c)	4.84 to 5.34	70,883,330,000	70,814,726,237
Freddie Mac
5/3/23 (c)(d)	4.94	795,750,000	795,750,000

TOTAL U.S. GOVERNMENT AGENCY DEBT (Cost $76,195,870,623)			76,195,870,623

U.S. Government Agency Repurchase Agreement - 14.7%
	Maturity Amount ($)	Value ($)
In a joint trading account at:
4.81% dated 4/28/23 due 5/1/23 (Collateralized by U.S. Government Obligations) #	13,303,594,702	13,298,266,000
4.82% dated 4/28/23 due 5/1/23 (Collateralized by U.S. Government Obligations) #	50,280,188	50,260,000
With:
ABN AMRO Bank NV at 4.81%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Government Obligations valued at $589,796,410, 2.50% - 6.50%, 12/1/26 - 4/1/53)	578,231,682	578,000,000
BMO Harris Bank NA at:
4.81%, dated:
3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $319,898,296, 5.00% - 5.50%, 4/1/53)	313,750,840	312,000,000
4/12/23 due 5/3/23 (Collateralized by U.S. Government Obligations valued at $285,302,439, 1.97% - 6.44%, 9/15/41 - 4/20/72)	279,782,828	279,000,000
4.99%, dated 4/24/23 due 5/5/23 (Collateralized by U.S. Government Obligations valued at $305,275,916, 3.86% - 6.63%, 9/20/71 - 2/20/73)	300,243,342	299,000,000
BNP Paribas, SA at:
4.8%, dated:
2/17/23 due 5/5/23 (Collateralized by U.S. Government Obligations valued at $571,785,601, 0.00% - 7.50%, 7/31/24 - 10/15/63)	561,586,000	555,000,000
4/24/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $222,567,572, 0.00% - 5.17%, 3/15/24 - 2/15/53)	218,203,467	218,000,000
4.81%, dated:
3/6/23 due 5/5/23 (Collateralized by U.S. Government Obligations valued at $1,728,450,694, 0.00% - 7.00%, 5/2/23 - 1/15/58)	1,695,135,109	1,681,000,000
4/20/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $2,409,732,845, 0.00% - 6.50%, 9/30/23 - 2/1/56)	2,363,408,054	2,359,000,000
4.82%, dated 4/4/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $314,606,572, 0.00% - 7.50%, 7/31/23 - 4/20/53)	307,229,100	306,000,000
4.84%, dated 4/28/23 due 5/5/23 (Collateralized by U.S. Government Obligations valued at $1,531,392,796, 0.00% - 7.00%, 5/30/23 - 4/20/53)	1,501,411,667	1,500,000,000
4.87%, dated 4/11/23 due 5/5/23 (Collateralized by U.S. Treasury Obligations valued at $199,979,606, 0.00% - 6.50%, 7/31/24 - 3/20/53)	195,791,375	195,000,000
4.91%, dated 3/3/23 due 5/5/23 (Collateralized by U.S. Government Obligations valued at $620,198,972, 0.00% - 7.00%, 6/15/23 - 10/15/63)	610,722,923	603,000,000
BNY Mellon Capital Markets Corp. at 4.84%, dated:
3/27/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $272,596,735, 0.00% - 6.00%, 5/2/23 - 5/1/53)	267,358,964	266,000,000
3/30/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $271,471,103, 0.00% - 6.00%, 5/15/23 - 5/1/53)	266,246,972	265,000,000
BofA Securities, Inc. at:
4.75%, dated 2/28/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $354,778,738, 3.00% - 5.50%, 6/20/51 - 1/20/53)	347,958,854	345,000,000
4.8%, dated 4/24/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $202,148,525, 1.38%, 12/31/28)	198,184,800	198,000,000
4.82%, dated:
4/18/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $398,491,288, 2.00%, 2/20/51) (c)(d)(e)	390,835,467	390,000,000
4/26/23 due 5/5/23 (Collateralized by U.S. Government Obligations valued at $318,452,868, 3.00% - 6.00%, 6/20/46 - 4/20/53) (c)(d)(e)	313,253,200	312,000,000
CIBC Bank U.S.A. at:
4.81%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $832,555,862, 1.13% - 7.00%, 7/1/27 - 7/1/60)	816,556,673	812,000,000
4.87%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $20,034,000, 0.00% - 6.50%, 7/15/25 - 5/15/58)	19,610,793	19,500,000
Citibank NA at 4.81%, dated 4/27/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $478,684,088, 0.00% - 6.00%, 6/30/24 - 4/1/53)	468,437,710	468,000,000
Citigroup Global Capital Markets, Inc. at 4.81%, dated:
3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $479,847,451, 1.38% - 7.50%, 6/30/23 - 3/20/53)	470,626,260	468,000,000
4/27/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $556,197,123, 0.00% - 6.75%, 7/10/23 - 1/25/38)	545,509,726	545,000,000
Goldman Sachs & Co. at 4.81%, dated:
4/24/23 due 5/1/23 (Collateralized by U.S. Government Obligations valued at $1,435,461,302, 0.00% - 7.00%, 9/14/23 - 11/15/57)	1,407,315,001	1,406,000,000
4/25/23 due 5/2/23 (Collateralized by U.S. Government Obligations valued at $956,506,186, 1.50% - 7.00%, 11/15/24 - 4/15/63)	937,876,355	937,000,000
4/26/23 due 5/3/23 (Collateralized by U.S. Government Obligations valued at $1,913,777,656, 1.50% - 6.50%, 3/1/34 - 4/20/53)	1,876,753,646	1,875,000,000
4/27/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $635,799,618, 2.50% - 7.00%, 5/1/30 - 4/1/53)	623,582,678	623,000,000
4/28/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $636,735,123, 1.50% - 7.50%, 7/20/26 - 11/15/64)	624,500,240	624,000,000
Mitsubishi UFJ Securities (U.S.A.), Inc. at 4.84%, dated 3/23/23 due 6/5/23 (Collateralized by U.S. Government Obligations valued at $1,298,155,129, 0.00% - 6.50%, 6/1/25 - 5/1/53)	1,273,148,680	1,266,000,000
RBC Dominion Securities at 4.81%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $1,534,896,630, 1.50% - 5.50%, 9/24/26 - 12/20/52)	1,505,400,665	1,497,000,000
RBC Financial Group at 4.81%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $2,894,288,612, 0.00% - 7.50%, 5/15/23 - 8/1/59)	2,834,819,288	2,819,000,000
TD Securities (U.S.A.) at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Government Obligations valued at $889,795,776, 1.50% - 7.00%, 8/1/23 - 4/1/53)	872,348,800	872,000,000
TOTAL U.S. GOVERNMENT AGENCY REPURCHASE AGREEMENT (Cost $38,241,026,000)		38,241,026,000

U.S. Treasury Repurchase Agreement - 52.1%
	Maturity Amount ($)	Value ($)
With:
ABN AMRO Bank NV at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $422,132,511, 2.00% - 5.25%, 2/15/25 - 11/15/48)	412,978,125	412,813,000
Barclays Bank PLC at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $2,844,897,532, 0.75% - 4.63%, 4/30/24 - 8/15/42)	2,789,115,200	2,788,000,000
BofA Securities, Inc. at 4.81%, dated 4/6/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $49,123,547, 0.88%, 11/15/30)	48,179,573	48,000,000
CIBC Bank U.S.A. at 4.81%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $901,762,769, 0.50% - 4.38%, 2/29/24 - 11/15/51)	880,910,710	876,000,000
Credit AG at 4.81%, dated 4/20/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $284,998,287, 0.88% - 2.25%, 3/31/26 - 9/30/26)	279,521,885	279,000,000
Federal Reserve Bank of New York at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $119,702,862,005, 1.88% - 4.50%, 5/15/38 - 5/15/52)	119,702,862,000	119,655,000,000
Fixed Income Clearing Corp. - BNYM at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $5,333,580,043, 0.00% - 4.75%, 7/11/23 - 5/15/51)	5,231,091,600	5,229,000,000
ING Financial Markets LLC at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $176,627,582, 1.13% - 2.75%, 8/31/25 - 11/15/29)	173,069,200	173,000,000
Lloyds Bank PLC at:
4.75%, dated:
2/6/23 due 5/9/23 (Collateralized by U.S. Treasury Obligations valued at $148,391,296, 0.75% - 2.50%, 11/15/24 - 8/15/27)	145,748,000	144,000,000
2/7/23 due 5/9/23 (Collateralized by U.S. Treasury Obligations valued at $91,706,860, 2.38% - 2.88%, 8/15/24 - 11/30/25)	90,068,618	89,000,000
4.77%, dated 3/2/23 due 5/2/23 (Collateralized by U.S. Treasury Obligations valued at $180,801,133, 2.50% - 2.88%, 1/31/25 - 8/15/28)	177,422,520	176,000,000
4.82%, dated 3/9/23 due 5/9/23 (Collateralized by U.S. Treasury Obligations valued at $181,672,898, 1.88% - 2.50%, 1/31/25 - 2/28/29)	178,445,598	177,000,000
4.84%, dated 3/27/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $142,340,307, 0.75% - 2.88%, 11/15/24 - 11/30/25)	139,710,136	139,000,000
4.86%, dated 3/16/23 due 5/16/23 (Collateralized by U.S. Treasury Obligations valued at $91,271,734, 2.00% - 3.25%, 1/31/25 - 6/30/27)	89,732,915	89,000,000
4.87%, dated 2/22/23 due 5/22/23 (Collateralized by U.S. Treasury Obligations valued at $146,054,900, 0.38%, 7/31/27)	143,709,641	142,000,000
4.9%, dated 2/28/23 due 5/30/23 (Collateralized by U.S. Treasury Obligations valued at $162,389,139, 2.88% - 3.25%, 6/30/27 - 8/15/28)	159,957,006	158,000,000
Mizuho Bank, Ltd. at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $714,096,286, 1.63%, 5/15/31)	697,278,800	697,000,000
MUFG Securities (Canada), Ltd. at 4.81%, dated 4/24/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $142,757,417, 0.25% - 6.13%, 8/15/24 - 2/15/52)	139,185,719	139,000,000
MUFG Securities EMEA PLC at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,066,632,567, 1.25% - 3.25%, 8/15/24 - 2/15/43)	1,046,418,400	1,046,000,000
Natixis SA at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $710,183,343, 0.50% - 4.75%, 11/30/23 - 11/15/52)	694,277,600	694,000,000
Norinchukin Bank at 4.85%, dated 4/25/23 due 5/2/23 (Collateralized by U.S. Treasury Obligations valued at $35,714,513, 2.75%, 5/31/29)	35,033,007	35,000,000
RBS Securities, Inc. at 4.8%, dated:
4/27/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $518,436,402, 0.00% - 5.17%, 5/4/23 - 11/15/32)	508,474,133	508,000,000
4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $119,564,343, 1.25% - 4.00%, 12/15/25 - 9/30/28)	117,219,869	117,173,000
SMBC Nikko Securities America, Inc. at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $714,310,368, 0.00% - 4.63%, 7/6/23 - 11/15/52)	700,280,000	700,000,000
Societe Generale at 4.8%, dated:
4/25/23 due 5/2/23 (Collateralized by U.S. Treasury Obligations valued at $268,014,291, 3.00%, 8/15/52)	260,242,667	260,000,000
4/27/23 due 5/3/23 (Collateralized by U.S. Treasury Obligations valued at $518,365,258, 1.88% - 3.00%, 2/15/42 - 5/15/52)	503,402,400	503,000,000
Sumitomo Mitsui Trust Bank Ltd. at 4.97%, dated 4/26/23 due 5/5/23 (Collateralized by U.S. Treasury Obligations valued at $63,437,626, 1.63%, 8/15/29)	62,119,832	62,000,000
TOTAL U.S. TREASURY REPURCHASE AGREEMENT (Cost $135,335,986,000)		135,335,986,000

TOTAL INVESTMENT IN SECURITIES - 99.5% (Cost $258,698,845,167)	258,698,845,167
NET OTHER ASSETS (LIABILITIES) - 0.5%	1,210,318,856
NET ASSETS - 100.0%	259,909,164,023

Legend

(a)	Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b)	Amount is stated in United States dollars unless otherwise noted.

(c)	Coupon rates for floating and adjustable rate securities reflect the rates in effect at period end.

(d)	Coupon is indexed to a floating interest rate which may be multiplied by a specified factor and/or subject to caps or floors.

(e)	The maturity amount is based on the rate at period end.

Investment Valuation

Other Information
# Additional information on each counterparty to the repurchase agreement is as follows:
Repurchase Agreement / Counterparty	Value ($)
$13,298,266,000 due 5/01/23 at 4.81%
BNY Mellon Capital Markets LLC	390,293,000
Bank of America, N.A.	1,127,525,000
BofA Securities, Inc.	802,685,000
Citigroup Global Markets, Inc.	783,003,000
HSBC Securities (USA), Inc.	140,958,000
JP Morgan Securities LLC	313,240,000
Mitsubishi UFJ Securities Holdings Ltd	313,240,000
Mizuho Securities USA, Inc.	109,634,000
Nomura Securities International	960,296,000
RBC Dominion Securities, Inc.	939,604,000
Sumitomo Mitsui Banking Corp.	4,541,439,000
Sumitomo Mitsui Banking Corp. NY	997,141,000
Wells Fargo Securities LLC	1,879,208,000
	13,298,266,000

$50,260,000 due 5/01/23 at 4.82%
BofA Securities, Inc.	50,260,000
	50,260,000

Statement of Assets and Liabilities
				April 30, 2023

Assets
Investment in securities, at value (including repurchase agreements of $173,577,012,000) - See accompanying schedule Unaffiliated issuers (cost $258,698,845,167):			$	258,698,845,167
Cash				628,000,861
Receivable for fund shares sold				1,908,686,574
Interest receivable				648,969,559
Prepaid expenses				84,046
Receivable from investment adviser for expense reductions				547,744
Other receivables				1,727,704
Total assets				261,886,861,655
Liabilities
Payable for investments purchased	$	450,000,000
Payable for fund shares redeemed		1,233,879,270
Distributions payable		197,370,560
Accrued management fee		53,683,901
Distribution and service plan fees payable		3,747,601
Other affiliated payables		33,503,601
Other payables and accrued expenses		5,512,699
Total Liabilities				1,977,697,632
Net Assets			$	259,909,164,023
Net Assets consist of:
Paid in capital			$	259,910,741,162
Total accumulated earnings (loss)				(1,577,139)
Net Assets			$	259,909,164,023

Net Asset Value and Maximum Offering Price
Capital Reserves Class :
Net Asset Value , offering price and redemption price per share ($5,294,932,488 ÷ 5,293,440,482 shares)			$	1.00
Daily Money Class :
Net Asset Value , offering price and redemption price per share ($7,151,811,842 ÷ 7,150,021,790 shares)			$	1.00
Advisor M Class :
Net Asset Value , offering price and redemption price per share ($172,226,948 ÷ 172,231,631 shares)			$	1.00
Fidelity Government Money Market Fund :
Net Asset Value , offering price and redemption price per share ($236,784,702,854 ÷ 236,781,545,167 shares)			$	1.00
Class S :
Net Asset Value , offering price and redemption price per share ($116,643,101 ÷ 116,643,941 shares)			$	1.00
Premium Class :
Net Asset Value , offering price and redemption price per share ($7,609,040,964 ÷ 7,607,212,570 shares)			$	1.00
Class K6 :
Net Asset Value , offering price and redemption price per share ($2,779,805,826 ÷ 2,779,868,710 shares)			$	1.00

Statement of Operations
				Year ended April 30, 2023
Investment Income
Interest			$	7,660,984,718
Expenses
Management fee	$	618,050,470
Transfer agent fees		398,095,029
Distribution and service plan fees		50,968,073
Accounting fees and expenses		5,656,012
Custodian fees and expenses		768,117
Independent trustees' fees and expenses		880,923
Registration fees		12,930,460
Audit		56,579
Legal		170,311
Miscellaneous		622,085
Total expenses before reductions		1,088,198,059
Expense reductions		(7,685,045)
Total expenses after reductions				1,080,513,014
Net Investment income (loss)				6,580,471,704
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment Securities:
Unaffiliated issuers		(1,421,339)
Total net realized gain (loss)				(1,421,339)
Net increase in net assets resulting from operations			$	6,579,050,365

Statement of Changes in Net Assets

		Year ended April 30, 2023		Year ended April 30, 2022
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$	6,580,471,704	$	23,906,078
Net realized gain (loss)		(1,421,339)		176,959
Net increase in net assets resulting from operations		6,579,050,365		24,083,037
Distributions to shareholders		(6,580,599,912)		(23,866,363)
Share transactions - net increase (decrease)		8,353,454,402		30,047,248,045
Total increase (decrease) in net assets		8,351,904,855		30,047,464,719

Net Assets
Beginning of period		251,557,259,168		221,509,794,449
End of period	$	259,909,164,023	$	251,557,259,168

Financial Highlights

Fidelity® Government Money Market Fund Capital Reserves Class

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.022		- B		- B		.009		.012
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.022		- B		- B		.009		.012
Distributions from net investment income		(.022)		- B		- B		(.009)		(.012)
Total distributions		(.022)		- B		- B		(.009)		(.012)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		2.20%		.01%		.01%		.94%		1.26%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.96%		.96%		.96%		.97%		.96%
Expenses net of fee waivers, if any		.92%		.10%		.15%		.89%		.95%
Expenses net of all reductions		.92%		.10%		.15%		.89%		.95%
Net investment income (loss)		2.18%		.01%		.01%		.87%		1.26%
Supplemental Data
Net assets, end of period (000 omitted)	$	5,294,932	$	7,465,539	$	7,539,252	$	7,470,316	$	6,491,629

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

Fidelity® Government Money Market Fund Daily Money Class

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.024		- B		- B		.012		.015
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.024		- B		- B		.012		.015
Distributions from net investment income		(.024)		- B		- B		(.012)		(.015)
Total distributions		(.024)		- B		- B		(.012)		(.015)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		2.43%		.01%		.01%		1.16%		1.51%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.71%		.71%		.71%		.72%		.71%
Expenses net of fee waivers, if any		.70%		.10%		.15%		.67%		.70%
Expenses net of all reductions		.70%		.10%		.15%		.67%		.70%
Net investment income (loss)		2.40%		.01%		.01%		1.08%		1.51%
Supplemental Data
Net assets, end of period (000 omitted)	$	7,151,812	$	7,389,338	$	7,356,206	$	7,835,091	$	6,038,320

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

Fidelity® Government Money Market Fund Advisor M Class

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.024		- B		- B		.012		.015
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.024		- B		- B		.012		.015
Distributions from net investment income		(.024)		- B		- B		(.012)		(.015)
Total distributions		(.024)		- B		- B		(.012)		(.015)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		2.43%		.01%		.01%		1.17%		1.52%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.71%		.71%		.71%		.72%		.71%
Expenses net of fee waivers, if any		.70%		.10%		.15%		.65%		.70%
Expenses net of all reductions		.70%		.10%		.15%		.64%		.69%
Net investment income (loss)		2.40%		.01%		.01%		1.12%		1.53%
Supplemental Data
Net assets, end of period (000 omitted)	$	172,227	$	148,512	$	124,205	$	126,269	$	50,630

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

Fidelity® Government Money Market Fund

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.027		- B		- B		.014		.018
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.027		- B		- B		.014		.018
Distributions from net investment income		(.027)		- B		- B		(.014)		(.018)
Total distributions		(.027)		- B		- B		(.014)		(.018)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		2.72%		.01%		.01%		1.42%		1.79%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.42%		.42%		.42%		.42%		.42%
Expenses net of fee waivers, if any		.42%		.10%		.15%		.42%		.42%
Expenses net of all reductions		.42%		.10%		.15%		.42%		.42%
Net investment income (loss)		2.68%		.01%		.01%		1.33%		1.79%
Supplemental Data
Net assets, end of period (000 omitted)	$	236,784,703	$	230,027,515	$	200,115,905	$	165,823,962	$	104,973,598

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

Fidelity® Government Money Market Fund Class S

Years ended April 30,		2023		2022 A
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) B		.027		- C
Net realized and unrealized gain (loss) C		-		-
Total from investment operations		.027		- C
Distributions from net investment income		(.027)		- C
Total distributions		(.027)		- C
Net asset value, end of period	$	1.00	$	1.00
Total Return D,E		2.72%		-% F
Ratios to Average Net Assets B,G,H
Expenses before reductions		.46%		.46% I
Expenses net of fee waivers, if any		.42%		.14% I
Expenses net of all reductions		.42%		.14% I
Net investment income (loss)		2.68%		.01% I
Supplemental Data
Net assets, end of period (000 omitted)	$	116,643	$	100

A For the period December 2, 2021 (commencement of sale of shares) through April 30, 2022.

B Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.

C Amount represents less than $.0005 per share.

D Total returns for periods of less than one year are not annualized.

E Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

F Amount represents less than .005%.

G Expense ratios reflect operating expenses of the class. Expenses before reductions do not reflect amounts reimbursed, waived, or reduced through arrangements with the investment adviser, brokerage services, or other offset arrangements, if applicable, and do not represent the amount paid by the class during periods when reimbursements, waivers or reductions occur.

H Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

I Annualized.

Fidelity® Government Money Market Fund Premium Class

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.028		- B		- B		.015		.019
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.028		- B		- B		.015		.019
Distributions from net investment income		(.028)		- B		- B		(.015)		(.019)
Total distributions		(.028)		- B		- B		(.015)		(.019)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		2.82%		.01%		.01%		1.52%		1.90%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.36%		.36%		.36%		.37%		.36%
Expenses net of fee waivers, if any		.32%		.09%		.15%		.32%		.32%
Expenses net of all reductions		.32%		.09%		.15%		.32%		.32%
Net investment income (loss)		2.78%		.01%		-% F		1.43%		1.89%
Supplemental Data
Net assets, end of period (000 omitted)	$	7,609,041	$	4,352,205	$	4,713,643	$	5,726,124	$	4,115,468

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

F Amount represents less than .005%.

Fidelity® Government Money Market Fund Class K6

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.029		- B		- B		.016		.019
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.029		- B		- B		.016		.019
Distributions from net investment income		(.029)		- B		- B		(.016)		(.019)
Total distributions		(.029)		- B		- B		(.016)		(.019)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		2.89%		.02%		.01%		1.59%		1.97%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.27%		.27%		.27%		.28%		.27%
Expenses net of fee waivers, if any		.25%		.09%		.14%		.25%		.25%
Expenses net of all reductions		.25%		.09%		.14%		.25%		.25%
Net investment income (loss)		2.85%		.02%		.01%		1.50%		1.96%
Supplemental Data
Net assets, end of period (000 omitted)	$	2,779,806	$	2,174,050	$	1,660,582	$	1,313,087	$	404,595

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

For the period ended April 30, 2023

1. Organization.

Fidelity Government Money Market Fund (the Fund) is a fund of Fidelity Hereford Street Trust (the Trust) and is authorized to issue an unlimited number of shares. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Delaware statutory trust. The Fund offers Capital Reserves Class, Daily Money Class, Advisor M Class, Fidelity Government Money Market Fund, Class S, Premium Class and Class K6 shares, each of which has equal rights as to assets and voting privileges. Each class has exclusive voting rights with respect to matters that affect that class. Class S shares are offered only to the Fidelity FDIC-Insured Deposit Sweep Program.

2. Significant Accounting Policies.

Investment Valuation. The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Investments in the Fidelity Central Funds are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Fidelity Government Money Market Fund

$1,727,704

Book-tax differences are primarily due to capital loss carryforwards and losses deferred due to wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities for federal income tax purposes were as follows:

Gross unrealized appreciation	$-
Gross unrealized depreciation	-
Net unrealized appreciation (depreciation)	$-
Tax Cost	$258,698,845,167

The tax-based components of distributable earnings as of period end were as follows:

Undistributed tax-exempt income	$-
Undistributed ordinary income	$-
Capital loss carryforward	$(1,564,377)
Net unrealized appreciation (depreciation) on securities and other investments	$-

Capital loss carryforwards are only available to offset future capital gains of the Fund to the extent provided by regulations and may be limited. The capital loss carryforward information presented below, including any applicable limitation, is estimated as of fiscal period end and is subject to adjustment.

Short-term	$(268,591)
Long-term	(1,295,787)
Total capital loss carryforward	$(1,564,377)

The tax character of distributions paid was as follows:

	April 30, 2023	April 30, 2022
Ordinary Income	$6,580,599,912	$23,866,363

Repurchase Agreements. Pursuant to an Exemptive Order issued by the Securities and Exchange Commission, funds and other registered investment companies having management contracts with Fidelity Management and Research Company LLC, or its affiliates are permitted to transfer uninvested cash balances into joint trading accounts which are then invested in repurchase agreements. Funds may also invest directly with institutions in repurchase agreements. Repurchase agreements may be collateralized by cash or government securities. Upon settlement date, collateral is held in segregated accounts with custodian banks and may be obtained in the event of a default of the counterparty. The collateral balance is monitored on a daily basis to ensure it is at least equal to the principal amount of the repurchase agreement (including accrued interest). In the event of a default by the counterparty, realization of the collateral proceeds could be delayed, during which time the value of the collateral may decline.

3. Fees and Other Transactions with Affiliates.

Management Fee and Expense Contract. Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund pays a monthly management fee that is based on an annual rate of .25% of the Fund's average net assets. Under the expense contract, total expenses of Fidelity Government Money Market Fund are limited to an annual rate of .42% of the class' average net assets, with certain exceptions.

Distribution and Service Plan Fees. In accordance with Rule 12b-1 of the 1940 Act, the Fund has adopted separate Distribution and Service Plans for each class of shares. Certain classes pay Fidelity Distributors Company LLC (FDC), an affiliate of the investment adviser, separate Distribution and Service Fees, each of which is based on an annual percentage of each class' average net assets. In addition, FDC may pay financial intermediaries for selling shares of the Fund and providing shareholder support services. For the period, the Distribution and Service Fee rates, total fees and amounts retained by FDC were as follows:

	Distribution Fee	Service Fee	Total Fees	Retained by FDC
Capital Reserves Class	.25%	.25%	$32,272,722	$19,033,312
Daily Money Class	- %	.25%	18,280,541	8,634,843
Advisor M Class	- %	.25%	414,810	38,729
			$50,968,073	$27,706,884

Sales Load. FDC receives the proceeds of contingent deferred sales charges for Daily Money Class shares purchased by exchange from Class A or Class M shares of a Fidelity fund that were subject to these charges. In addition, FDC receives deferred sales charges for Advisor M Class shares purchased by exchange from Class M shares of a Fidelity fund that were subject to these charges.

For the period, sales charge amounts retained by FDC were as follows:

	Retained by FDC
Daily Money Class	$36,540
Advisor M Class	$35

Transfer Agent Fees. Fidelity Investments Institutional Operations Company LLC (FIIOC), an affiliate of the investment adviser, is the transfer, dividend disbursing and shareholder servicing agent for each class of the Fund. FIIOC receives asset-based fees with respect to each account. FIIOC pays for typesetting, printing and mailing of shareholder reports, except proxy statements. Each class pays a transfer agent fee equal to an annual rate of .20% of class-level average net assets, with the exception of Premium Class and Class K6 which pays .10% and .01% of class-level average net assets, respectively.

Under the expense contract, Fidelity Government Money Market Fund will pay a portion of the transfer agent fee at an annual rate of up to .17% of class-level average net assets.

For the period, transfer agent fees for each class were as follows:

	Amount	% of Class-Level Average Net Assets
Capital Reserves Class	$12,909,089	.20
Daily Money Class	14,624,433	.20
Advisor M Class	331,848	.20
Fidelity Government Money Market Fund	364,330,967	.16
Class S	207,448	.20
Premium Class	5,441,647	.10
Class K6	249,597	.01
	$398,095,029

During the period, the investment adviser or its affiliates waived a portion of these fees.

	% of Average Net Assets
Fidelity Government Money Market Fund	- A

A Amount represents less than .005%.

	Purchases ($)	Sales ($)	Realized Gain (Loss) ($)
Fidelity Government Money Market Fund	-	75,145,000	-

4. Expense Reductions.

The investment adviser contractually agreed to reimburse expenses of each class to the extent annual operating expenses exceeded certain levels of class-level average net assets as noted in the table below. Some expenses, for example the compensation of the independent Trustees, and certain other expenses such as interest expense, are excluded from this reimbursement.

The following classes were in reimbursement during the period:

	Expense Limitations	Reimbursement	Expiration Date
Capital Reserves Class	.95%	$467,311	August 31, 2024
Daily Money Class	.70%	606,433	August 31, 2024
Advisor M Class	.70%	13,386	August 31, 2024
Class S	.42%	39,851	August 31, 2024
Premium Class	.32%	2,114,661	August 31, 2024
Class K6	.25%	457,899	August 31, 2024
		$3,699,541

Additionally, the investment adviser or its affiliates voluntarily agreed to waive certain fees in order to avoid a negative yield. Such arrangements may be discontinued by the investment adviser at any time. For the period, the amount of the waiver for each class was as follows:

Capital Reserves Class	$1,889,478
Daily Money Class	284,773
Advisor M Class	5,704
Fidelity Government Money Market Fund	1,722,312
Class S	1

Through arrangements with the Fund's custodian, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses. During the period, custodian credits reduced the Fund's expenses by $64,296. During the period, transfer agent credits reduced each class' expenses as noted in the table below.

	Expense reduction

Daily Money Class	$602

In addition, during the period the investment adviser or an affiliate reimbursed and/or waived a portion of fund-level operating expenses in the amount of $18,338.

5. Distributions to Shareholders.

Distributions to shareholders of each class were as follows:

	Year ended April 30, 2023	Year ended April 30, 2022 A
Fidelity Government Money Market Fund
Distributions to shareholders
Capital Reserves Class	$ 132,294,501	$758,597
Daily Money Class	173,911,146	748,324
Advisor M Class	4,026,868	13,196
Fidelity Government Money Market Fund	6,032,133,212	21,569,064
Class S	3,127,896	4
Premium Class	161,984,763	452,225
Class K6	73,121,526	324,953
Total	$6,580,599,912	$23,866,363

A Distributions for Class S are for the period December 2, 2021 (commencement of sale of shares) through April 30, 2022.

6. Share Transactions.

Share transactions for each class of shares at a $1.00 per share were as follows and may contain in-kind transactions, automatic conversions between classes or exchanges between affiliated funds:

	Shares	Shares	Dollars	Dollars
	Year ended April 30, 2023	Year ended April 30, 2022 A	Year ended April 30, 2023	Year ended April 30, 2022 A
Fidelity Government Money Market Fund
Capital Reserves Class
Shares sold	24,726,485,347	27,391,386,975	$24,726,485,347	$27,391,386,975
Reinvestment of distributions	82,299,780	460,810	82,299,780	460,810
Shares redeemed	(26,978,689,833)	(27,465,582,704)	(26,978,689,833)	(27,465,582,704)
Net increase (decrease)	(2,169,904,706)	(73,734,919)	$(2,169,904,706)	$(73,734,919)
Daily Money Class
Shares sold	29,426,737,018	26,738,209,273	$29,426,737,018	$26,738,209,273
Reinvestment of distributions	124,369,442	516,833	124,369,442	516,833
Shares redeemed	(29,788,519,287)	(26,705,576,696)	(29,788,519,287)	(26,705,576,695)
Net increase (decrease)	(237,412,827)	33,149,410	$(237,412,827)	$33,149,411
Advisor M Class
Shares sold	146,781,874	155,775,755	$146,781,874	$155,775,755
Reinvestment of distributions	3,948,140	12,811	3,948,140	12,811
Shares redeemed	(127,013,170)	(131,481,710)	(127,013,170)	(131,481,711)
Net increase (decrease)	23,716,844	24,306,856	$23,716,844	$24,306,855
Fidelity Government Money Market Fund
Shares sold	747,228,976,266	718,100,082,282	$747,228,976,259	$718,100,082,261
Reinvestment of distributions	4,973,485,810	19,163,112	4,973,485,810	19,163,113
Shares redeemed	(745,443,820,532)	(688,207,963,906)	(745,443,820,524)	(688,207,963,886)
Net increase (decrease)	6,758,641,544	29,911,281,488	$6,758,641,545	$29,911,281,488
Class S
Shares sold	1,009,671,977	106,813	$1,009,671,977	$106,813
Reinvestment of distributions	2,753,148	4	2,753,148	4
Shares redeemed	(895,881,428)	(6,573)	(895,881,428)	(6,573)
Net increase (decrease)	116,543,697	100,244	$116,543,697	$100,244
Premium Class
Shares sold	7,637,912,164	2,009,205,919	$7,637,912,162	$2,009,205,914
Reinvestment of distributions	147,283,681	431,259	147,283,681	431,259
Shares redeemed	(4,529,107,357)	(2,370,975,882)	(4,529,107,803)	(2,370,975,877)
Net increase (decrease)	3,256,088,488	(361,338,704)	$3,256,088,040	$(361,338,704)
Class K6
Shares sold	2,269,895,570	1,794,922,596	$2,269,895,570	$1,794,922,596
Reinvestment of distributions	73,121,526	316,317	73,121,526	316,317
Shares redeemed	(1,737,235,287)	(1,281,755,243)	(1,737,235,287)	(1,281,755,243)
Net increase (decrease)	605,781,809	513,483,670	$605,781,809	$513,483,670

A Share transactions for Class S are for the period December 2, 2021 (commencement of sale of shares) through April 30, 2022.

7. Other.

8. Risk and Uncertainties.

Report of Independent Registered Public Accounting Firm

To the Board of Trustees of Fidelity Hereford Street Trust and Shareholders of Fidelity Government Money Market Fund

Opinion on the Financial Statements

We have audited the accompanying statement of assets and liabilities, including the schedule of investments, of Fidelity Government Money Market Fund (one of the funds constituting Fidelity Hereford Street Trust, referred to hereafter as the "Fund") as of April 30, 2023, the related statement of operations for the year ended April 30, 2023, the statement of changes in net assets for each of the two years in the period ended April 30, 2023, including the related notes, and the financial highlights for each of the periods indicated therein (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Fund as of April 30, 2023, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period ended April 30, 2023 and the financial highlights for each of the periods indicated therein in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts

June 13, 2023

We have served as the auditor of one or more investment companies in the Fidelity group of funds since 1932.

TRUSTEES AND OFFICERS

The fund's Statement of Additional Information (SAI) includes more information about the Trustees. To request a free copy, call Fidelity at 1-800-544-8544 if you're an individual investing directly with Fidelity, call 1-800-835-5092 if you're a plan sponsor or participant with Fidelity as your recordkeeper or call 1-877-208-0098 on institutional accounts or if you're an advisor or invest through one.

Interested Trustees*:

Correspondence intended for a Trustee who is an interested person may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Abigail P. Johnson (1961)

Year of Election or Appointment: 2009

Trustee

Chairman of the Board of Trustees

Jennifer Toolin McAuliffe (1959)

Year of Election or Appointment: 2016

Trustee

* Determined to be an "Interested Trustee" by virtue of, among other things, his or her affiliation with the trust or various entities under common control with FMR.

Independent Trustees:

Correspondence intended for an Independent Trustee may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Elizabeth S. Acton (1951)

Year of Election or Appointment: 2013

Trustee

Ann E. Dunwoody (1953)

Year of Election or Appointment: 2018

Trustee

John Engler (1948)

Year of Election or Appointment: 2014

Trustee

Robert F. Gartland (1951)

Year of Election or Appointment: 2010

Trustee

Arthur E. Johnson (1947)

Year of Election or Appointment: 2008

Trustee

Michael E. Kenneally (1954)

Year of Election or Appointment: 2009

Trustee

Chairman of the Independent Trustees

Mark A. Murray (1954)

Year of Election or Appointment: 2016

Trustee

Advisory Board Members and Officers:

Name, Year of Birth; Principal Occupation

Laura M. Bishop (1961)

Year of Election or Appointment: 2022

Member of the Advisory Board

Robert W. Helm (1957)

Year of Election or Appointment: 2021

Member of the Advisory Board

Carol J. Zierhoffer (1960)

Year of Election or Appointment: 2023

Member of the Advisory Board

Heather Bonner (1977)

Year of Election or Appointment: 2023

Assistant Treasurer

Craig S. Brown (1977)

Year of Election or Appointment: 2019

Assistant Treasurer

John J. Burke III (1964)

Year of Election or Appointment: 2018

Chief Financial Officer

Margaret Carey (1973)

Year of Election or Appointment: 2023

Secretary and Chief Legal Officer (CLO)

David J. Carter (1973)

Year of Election or Appointment: 2020

Assistant Secretary

Jonathan Davis (1968)

Year of Election or Appointment: 2010

Assistant Treasurer

Laura M. Del Prato (1964)

Year of Election or Appointment: 2018

President and Treasurer

Christopher M. Gouveia (1973)

Year of Election or Appointment: 2023

Chief Compliance Officer

Colm A. Hogan (1973)

Year of Election or Appointment: 2016

Assistant Treasurer

Chris Maher (1972)

Year of Election or Appointment: 2013

Assistant Treasurer

Jamie Pagliocco (1964)

Year of Election or Appointment: 2020

Vice President

Brett Segaloff (1972)

Year of Election or Appointment: 2021

Anti-Money Laundering (AML) Officer

Stacie M. Smith (1974)

Year of Election or Appointment: 2013

Assistant Treasurer

Jim Wegmann (1979)

Year of Election or Appointment: 2021

Deputy Treasurer

Shareholder Expense Example

The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (November 1, 2022 to April 30, 2023).

Actual Expenses

Hypothetical Example for Comparison Purposes

	Annualized Expense Ratio- A	Beginning Account Value November 1, 2022	Ending Account Value April 30, 2023	Expenses Paid During Period- C November 1, 2022 to April 30, 2023
Fidelity® Government Money Market Fund
Capital Reserves Class	.95%
Actual		$ 1,000	$ 1,017.10	$ 4.75
Hypothetical- B		$ 1,000	$ 1,020.08	$ 4.76
Daily Money Class	.70%
Actual		$ 1,000	$ 1,018.40	$ 3.50
Hypothetical- B		$ 1,000	$ 1,021.32	$ 3.51
Advisor M Class	.70%
Actual		$ 1,000	$ 1,018.40	$ 3.50
Hypothetical- B		$ 1,000	$ 1,021.32	$ 3.51
Fidelity® Government Money Market Fund	.42%
Actual		$ 1,000	$ 1,019.80	$ 2.10
Hypothetical- B		$ 1,000	$ 1,022.71	$ 2.11
Class S	.42%
Actual		$ 1,000	$ 1,019.80	$ 2.10
Hypothetical- B		$ 1,000	$ 1,022.71	$ 2.11
Premium Class	.32%
Actual		$ 1,000	$ 1,020.30	$ 1.60
Hypothetical- B		$ 1,000	$ 1,023.21	$ 1.61
Class K6	.25%
Actual		$ 1,000	$ 1,020.70	$ 1.25
Hypothetical- B		$ 1,000	$ 1,023.55	$ 1.25

A Annualized expense ratio reflects expenses net of applicable fee waivers.

B 5% return per year before expenses

Distributions (Unaudited)

The dividend and capital gains distributions for the fund(s) are available on Fidelity.com or Institutional.Fidelity.com .

A total of 30.02% of the dividends distributed during the fiscal year was derived from interest on U.S. Government securities which is generally exempt from state income tax.

The fund designates $2,929,218,202 of distributions paid in the calendar year 2022 as qualifying to be taxed as interest-related dividends for nonresident alien shareholders.

The fund designates $6,580,599,910 of distributions paid during the fiscal year ended 2023 as qualifying to be taxed as section 163(j) interest dividends.

The fund will notify shareholders in January 2024 of amounts for use in preparing 2023 income tax returns.

1.703529.125

SPU-ANN-0623

Fidelity® Treasury Only Money Market Fund

Annual Report

April 30, 2023

Contents

Report of Independent Registered Public Accounting Firm

You may also call 1-800-544-8544 to request a free copy of the proxy voting guidelines.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Fund nor Fidelity Distributors Corporation is a bank.

Investment Summary/Performance April 30, 2023 (Unaudited)

Current 7-Day Yields

Fidelity® Treasury Only Money Market Fund	4.03%

Yield refers to the income paid by the Fund over a given period. Yield for money market funds is usually for seven-day periods, as it is here, though it is expressed as an annual percentage rate. Past performance is no guarantee of future results. Yield will vary and it's possible to lose money investing in the Fund.

Effective Maturity Diversification (% of Fund's Investments)
Days
1 - 7	16.0
8 - 30	84.0
Effective maturity is determined in accordance with the requirements of Rule 2a-7 under the Investment Company Act of 1940.

Asset Allocation (% of Fund's net assets)

Net Other Assets (Liabilities) - (13.6)%

Net Other Assets (Liabilities) are not available in the pie chart.

Showing Percentage of Net Assets

U.S. Treasury Debt - 113.6%
	Yield (%)(a)	Principal Amount (b) (000s)	Value ($) (000s)
U.S. Treasury Obligations - 113.6%
U.S. Treasury Bills
5/2/23 to 5/30/23	3.17 to 4.95	4,586,142	4,577,212
U.S. Treasury Notes
5/15/23 to 10/31/24 (c)	4.95 to 5.27	133,835	133,740

TOTAL U.S. TREASURY DEBT (Cost $4,710,952)			4,710,952

TOTAL INVESTMENT IN SECURITIES - 113.6% (Cost $4,710,952)	4,710,952
NET OTHER ASSETS (LIABILITIES) - (13.6)%	(563,987)
NET ASSETS - 100.0%	4,146,965

Legend

(a)	Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b)	Amount is stated in United States dollars unless otherwise noted.

(c)	Coupon rates for floating and adjustable rate securities reflect the rates in effect at period end.

Investment Valuation

Statement of Assets and Liabilities
Amounts in thousands (except per-share amount)				April 30, 2023

Assets
Investment in securities, at value - See accompanying schedule Unaffiliated issuers (cost $4,710,952):			$	4,710,952
Cash				190,758
Receivable for investments sold				92,094
Receivable for fund shares sold				12,292
Interest receivable				1,213
Total assets				5,007,309
Liabilities
Payable for investments purchased	$	841,735
Payable for fund shares redeemed		14,955
Distributions payable		2,197
Accrued management fee		1,457
Total Liabilities				860,344
Net Assets			$	4,146,965
Net Assets consist of:
Paid in capital			$	4,146,961
Total accumulated earnings (loss)				4
Net Assets			$	4,146,965
Net Asset Value , offering price and redemption price per share ($4,146,965 ÷ 4,146,179 shares)			$	1.00

Statement of Operations
Amounts in thousands				Year ended April 30, 2023
Investment Income
Interest			$	98,111
Expenses
Management fee	$	13,632
Independent trustees' fees and expenses		11
Total Expenses				13,643
Net Investment income (loss)				84,468
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment Securities:
Unaffiliated issuers		25
Total net realized gain (loss)				25
Net increase in net assets resulting from operations			$	84,493

Statement of Changes in Net Assets

Amount in thousands		Year ended April 30, 2023		Year ended April 30, 2022
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$	84,468	$	376
Net realized gain (loss)		25		(37)
Net increase in net assets resulting from operations		84,493		339
Distributions to shareholders		(84,477)		(446)
Share transactions
Proceeds from sales of shares		3,538,536		1,393,057
Reinvestment of distributions		75,134		405
Cost of shares redeemed		(2,866,760)		(1,797,612)
Net increase (decrease) in net assets and shares resulting from share transactions		746,910		(404,150)
Total increase (decrease) in net assets		746,926		(404,257)

Net Assets
Beginning of period		3,400,039		3,804,296
End of period	$	4,146,965	$	3,400,039

Other Information
Shares
Sold		3,538,536		1,393,057
Issued in reinvestment of distributions		75,134		405
Redeemed		(2,866,760)		(1,797,612)
Net increase (decrease)		746,910		(404,150)

Financial Highlights

Fidelity® Treasury Only Money Market Fund

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.026		- B		- B		.014		.018
Net realized and unrealized gain (loss) B		-		-		-		-		-
Total from investment operations		.026		-		- B		.014		.018
Distributions from net investment income		(.026)		- B		- B		(.014)		(.018)
Distributions from net realized gain		-		- B		-		-		-
Total distributions		(.026)		- B		- B		(.014)		(.018)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		2.62%		.01%		.01%		1.39%		1.79%
Ratios to Average Net Assets A,D,E
Expenses before reductions		.42%		.42%		.42%		.42%		.42%
Expenses net of fee waivers, if any		.42%		.11%		.15%		.42%		.42%
Expenses net of all reductions		.42%		.11%		.15%		.42%		.42%
Net investment income (loss)		2.60%		.01%		.01%		1.27%		1.76%
Supplemental Data
Net assets, end of period (in millions)	$	4,147	$	3,400	$	3,804	$	5,045	$	2,823

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

For the period ended April 30, 2023

(Amounts in thousands except percentages)

1. Organization.

Fidelity Treasury Only Money Market Fund (the Fund) is a fund of Fidelity Hereford Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Share transactions on the Statement of Changes in Net Assets may contain exchanges between affiliated funds. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Delaware statutory trust.

2. Significant Accounting Policies.

Investment Valuation. The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Expenses. Expenses directly attributable to a fund are charged to that fund. Expenses attributable to more than one fund are allocated among the respective funds on the basis of relative net assets or other appropriate methods. Expenses included in the accompanying financial statements reflect the expenses of that fund and do not include any expenses associated with any underlying mutual funds or exchange-traded funds. Although not included in a fund's expenses, a fund indirectly bears its proportionate share of these expenses through the net asset value of each underlying mutual fund or exchange-traded fund. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP. In addition, the Fund claimed a portion of the payment made to redeeming shareholders as a distribution for income tax purposes.

Book-tax differences are primarily due to capital loss carryforward and wash sales.

As of period end, the cost and unrealized appreciation (depreciation) in securities for federal income tax purposes were as follows:

Gross unrealized appreciation	$-
Gross unrealized depreciation	-
Net unrealized appreciation (depreciation)	$-
Tax Cost	$4,710,952

The tax-based components of distributable earnings as of period end were as follows:

Undistributed tax-exempt income	$-
Undistributed ordinary income	$10
Net unrealized appreciation (depreciation) on securities and other investments	$-

The tax character of distributions paid was as follows:

	April 30, 2023	April 30, 2022
Ordinary Income	$84,477	$446

3. Fees and Other Transactions with Affiliates.

Management Fee. Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund pays a monthly management fee that is based on an annual rate of .42% of the Fund's average net assets. Under the management contract, the investment adviser pays all other expenses, except the compensation of the independent Trustees and certain other expenses such as interest expense. The management fee is reduced by an amount equal to the fees and expenses paid by the Fund to the independent Trustees.

4. Other.

5. Risk and Uncertainties.

Report of Independent Registered Public Accounting Firm

To the Board of Trustees of Fidelity Hereford Street Trust and Shareholders of Fidelity Treasury Only Money Market Fund

Opinion on the Financial Statements

We have audited the accompanying statement of assets and liabilities, including the schedule of investments, of Fidelity Treasury Only Money Market Fund (one of the funds constituting Fidelity Hereford Street Trust, referred to hereafter as the "Fund") as of April 30, 2023, the related statement of operations for the year ended April 30, 2023, the statement of changes in net assets for each of the two years in the period ended April 30, 2023, including the related notes, and the financial highlights for each of the five years in the period ended April 30, 2023 (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Fund as of April 30, 2023, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period ended April 30, 2023 and the financial highlights for each of the five years in the period ended April 30, 2023 in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. Our procedures included confirmation of securities owned as of April 30, 2023 by correspondence with the custodian and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts

June 12, 2023

We have served as the auditor of one or more investment companies in the Fidelity group of funds since 1932.

TRUSTEES AND OFFICERS

The fund's Statement of Additional Information (SAI) includes more information about the Trustees. To request a free copy, call Fidelity at 1-800-544-8544.

Interested Trustees*:

Correspondence intended for a Trustee who is an interested person may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Abigail P. Johnson (1961)

Year of Election or Appointment: 2009

Trustee

Chairman of the Board of Trustees

Jennifer Toolin McAuliffe (1959)

Year of Election or Appointment: 2016

Trustee

* Determined to be an "Interested Trustee" by virtue of, among other things, his or her affiliation with the trust or various entities under common control with FMR.

Independent Trustees:

Correspondence intended for an Independent Trustee may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Elizabeth S. Acton (1951)

Year of Election or Appointment: 2013

Trustee

Ann E. Dunwoody (1953)

Year of Election or Appointment: 2018

Trustee

John Engler (1948)

Year of Election or Appointment: 2014

Trustee

Robert F. Gartland (1951)

Year of Election or Appointment: 2010

Trustee

Arthur E. Johnson (1947)

Year of Election or Appointment: 2008

Trustee

Michael E. Kenneally (1954)

Year of Election or Appointment: 2009

Trustee

Chairman of the Independent Trustees

Mark A. Murray (1954)

Year of Election or Appointment: 2016

Trustee

Advisory Board Members and Officers:

Name, Year of Birth; Principal Occupation

Laura M. Bishop (1961)

Year of Election or Appointment: 2022

Member of the Advisory Board

Robert W. Helm (1957)

Year of Election or Appointment: 2021

Member of the Advisory Board

Carol J. Zierhoffer (1960)

Year of Election or Appointment: 2023

Member of the Advisory Board

Heather Bonner (1977)

Year of Election or Appointment: 2023

Assistant Treasurer

Craig S. Brown (1977)

Year of Election or Appointment: 2019

Assistant Treasurer

John J. Burke III (1964)

Year of Election or Appointment: 2018

Chief Financial Officer

Margaret Carey (1973)

Year of Election or Appointment: 2023

Secretary and Chief Legal Officer (CLO)

David J. Carter (1973)

Year of Election or Appointment: 2020

Assistant Secretary

Jonathan Davis (1968)

Year of Election or Appointment: 2010

Assistant Treasurer

Laura M. Del Prato (1964)

Year of Election or Appointment: 2018

President and Treasurer

Christopher M. Gouveia (1973)

Year of Election or Appointment: 2023

Chief Compliance Officer

Colm A. Hogan (1973)

Year of Election or Appointment: 2016

Assistant Treasurer

Chris Maher (1972)

Year of Election or Appointment: 2013

Assistant Treasurer

Jamie Pagliocco (1964)

Year of Election or Appointment: 2020

Vice President

Brett Segaloff (1972)

Year of Election or Appointment: 2021

Anti-Money Laundering (AML) Officer

Stacie M. Smith (1974)

Year of Election or Appointment: 2013

Assistant Treasurer

Jim Wegmann (1979)

Year of Election or Appointment: 2021

Deputy Treasurer

Shareholder Expense Example

The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (November 1, 2022 to April 30, 2023).

Actual Expenses

Hypothetical Example for Comparison Purposes

	Annualized Expense Ratio- A	Beginning Account Value November 1, 2022	Ending Account Value April 30, 2023	Expenses Paid During Period- C November 1, 2022 to April 30, 2023

Fidelity® Treasury Only Money Market Fund	.42%
Actual		$ 1,000	$ 1,019.20	$ 2.10
Hypothetical- B		$ 1,000	$ 1,022.71	$ 2.11

A Annualized expense ratio reflects expenses net of applicable fee waivers.

B 5% return per year before expenses

Distributions (Unaudited)

The dividend and capital gains distributions for the fund(s) are available on Fidelity.com or Institutional.Fidelity.com .

A total of 93.93% of the dividends distributed during the fiscal year was derived from interest on U.S. Government securities which is generally exempt from state income tax.

The fund designates $36,060,041 of distributions paid in the calendar year 2022 as qualifying to be taxed as interest-related dividends for nonresident alien shareholders.

The fund designates $84,468,141 of distributions paid during the fiscal year ended 2023 as qualifying to be taxed as section 163(j) interest dividends.

The fund will notify shareholders in January 2024 of amounts for use in preparing 2023 income tax returns.

1.703531.125

TMM-ANN-0623

Fidelity Flex® Funds

Fidelity Flex® Government Money Market Fund

Annual Report

April 30, 2023

Contents

Report of Independent Registered Public Accounting Firm

You may also call 1-800-544-3455 (for managed account clients) or 1-800-835-5092 (for retirement plan participants) to request a free copy of the proxy voting guidelines.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Fund nor Fidelity Distributors Corporation is a bank.

Investment Summary/Performance April 30, 2023 (Unaudited)

Current 7-Day Yields

Fidelity Flex® Government Money Market Fund	4.92%

Yield refers to the income paid by the Fund over a given period. Yield for money market funds is usually for seven-day periods, as it is here, though it is expressed as an annual percentage rate. Past performance is no guarantee of future results. Yield will vary and it's possible to lose money investing in the Fund.

Effective Maturity Diversification (% of Fund's Investments)
Days
1 - 7	94.7
31 - 60	1.0
61 - 90	1.1
91 - 180	0.5
> 180	2.7
Effective maturity is determined in accordance with the requirements of Rule 2a-7 under the Investment Company Act of 1940.

Asset Allocation (% of Fund's net assets)

Showing Percentage of Net Assets

U.S. Treasury Debt - 1.5%
	Yield (%)(a)	Principal Amount (b)	Value ($)
U.S. Treasury Obligations - 1.5%
U.S. Treasury Notes
10/31/24 (c)	5.27	1,500,000	1,501,176

TOTAL U.S. TREASURY DEBT (Cost $1,501,176)			1,501,176

U.S. Government Agency Debt - 30.0%
	Yield (%)(a)	Principal Amount (b)	Value ($)
Federal Agencies - 30.0%
Federal Farm Credit Bank
9/26/23 to 7/26/24 (c)(d)	4.87 to 4.96	3,350,000	3,349,938
Federal Home Loan Bank
5/22/23 to 11/22/24 (c)	4.85 to 5.33	26,500,000	26,477,433
Freddie Mac
5/3/23 (c)(d)	4.94	250,000	250,000

TOTAL U.S. GOVERNMENT AGENCY DEBT (Cost $30,077,371)			30,077,371

U.S. Government Agency Repurchase Agreement - 50.5%
	Maturity Amount ($)	Value ($)
In a joint trading account at 4.8% dated 4/28/23 due 5/1/23 (Collateralized by U.S. Government Obligations) #	30,087,034	30,075,000
With:
ABN AMRO Bank NV at 4.81%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Government Obligations valued at $1,020,409, 3.00% - 5.00%, 3/1/50 - 10/20/52)	1,000,401	1,000,000
BMO Harris Bank NA at 4.81%, dated 4/12/23 due 5/3/23 (Collateralized by U.S. Government Obligations valued at $1,022,590, 3.50%, 7/20/44)	1,002,806	1,000,000
BNP Paribas, SA at:
4.81%, dated 3/6/23 due 5/5/23 (Collateralized by U.S. Treasury Obligations valued at $1,035,265, 0.00% - 6.00%, 9/15/24 - 4/1/53)	1,008,409	1,000,000
4.82%, dated 4/4/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $1,023,926, 0.00% - 5.50%, 11/15/33 - 10/20/51)	1,004,017	1,000,000
4.84%, dated 4/28/23 due 5/5/23 (Collateralized by U.S. Government Obligations valued at $1,020,500, 0.00% - 6.00%, 10/26/23 - 4/1/53)	1,000,941	1,000,000
4.87%, dated 4/11/23 due 5/5/23 (Collateralized by U.S. Treasury Obligations valued at $1,032,545, 0.00% - 5.50%, 2/15/34 - 4/1/53)	1,004,058	1,000,000
4.91%, dated 3/3/23 due 5/5/23 (Collateralized by U.S. Government Obligations valued at $1,028,204, 2.00% - 6.00%, 7/31/24 - 4/20/53)	1,012,808	1,000,000
BNY Mellon Capital Markets Corp. at 4.84%, dated 3/30/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $1,024,479, 0.00% - 4.00%, 8/10/23 - 2/1/52)	1,004,706	1,000,000
BofA Securities, Inc. at:
4.8%, dated 4/24/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,020,979, 2.25%, 11/15/25)	1,000,933	1,000,000
4.82%, dated:
4/18/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $1,021,852, 2.25%, 11/15/25) (c)(d)(e)	1,002,142	1,000,000
4/26/23 due 5/5/23 (Collateralized by U.S. Treasury Obligations valued at $1,020,687, 2.25%, 11/15/25) (c)(d)(e)	1,004,017	1,000,000
CIBC Bank U.S.A. at:
4.81%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $1,025,340, 0.75% - 5.44%, 7/31/23 - 5/15/58)	1,005,612	1,000,000
4.87%, dated 3/23/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $513,336, 0.75% - 5.44%, 7/15/25 - 5/15/58)	502,841	500,000
Citibank NA at 4.81%, dated 4/27/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $1,027,039, 0.13% - 6.13%, 5/15/23 - 8/15/51)	1,000,935	1,000,000
Citigroup Global Capital Markets, Inc. at 4.81%, dated 4/27/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $1,020,639, 4.29% - 6.95%, 3/20/73)	1,000,935	1,000,000
Goldman Sachs & Co. at 4.81%, dated:
4/24/23 due 5/1/23 (Collateralized by U.S. Government Obligations valued at $1,020,954, 2.00% - 2.50%, 5/20/51 - 12/1/52)	1,000,935	1,000,000
4/25/23 due 5/2/23 (Collateralized by U.S. Treasury Obligations valued at $1,020,892, 4.00% - 6.00%, 10/31/29 - 5/1/42)	1,000,935	1,000,000
4/26/23 due 5/3/23 (Collateralized by U.S. Government Obligations valued at $1,020,681, 4.00%, 8/15/57)	1,000,935	1,000,000
4/27/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $1,020,546, 2.25% - 6.50%, 10/1/27 - 12/1/49)	1,000,935	1,000,000
4/28/23 due 5/4/23 (Collateralized by U.S. Government Obligations valued at $1,020,409, 3.00% - 5.00%, 8/1/34 - 1/20/48)	1,000,802	1,000,000
TD Securities (U.S.A.) at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Government Obligations valued at $1,020,408, 3.00%, 8/20/51)	1,000,400	1,000,000
TOTAL U.S. GOVERNMENT AGENCY REPURCHASE AGREEMENT (Cost $50,575,000)		50,575,000

U.S. Treasury Repurchase Agreement - 14.0%
	Maturity Amount ($)	Value ($)
With:
ABN AMRO Bank NV at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,020,453, 0.50% - 5.25%, 8/15/25 - 11/15/28)	1,000,400	1,000,000
Barclays Bank PLC at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,020,410, 4.63%, 2/15/40)	1,000,400	1,000,000
Credit AG at 4.81%, dated 4/20/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $1,021,512, 4.63%, 3/15/26)	1,001,871	1,000,000
Fixed Income Clearing Corp. - BNYM at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $2,040,060, 3.88%, 1/15/26)	2,000,800	2,000,000
ING Financial Markets LLC at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,021,437, 4.13%, 9/30/27)	1,000,400	1,000,000
Lloyds Bank PLC at 4.77%, dated 3/2/23 due 5/2/23 (Collateralized by U.S. Treasury Obligations valued at $1,029,034, 0.75% - 3.25%, 11/15/24 - 6/30/27)	1,008,083	1,000,000
Mizuho Bank, Ltd. at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,026,306, 1.25%, 8/15/31)	1,000,400	1,000,000
MUFG Securities (Canada), Ltd. at 4.81%, dated 4/24/23 due 5/4/23 (Collateralized by U.S. Treasury Obligations valued at $1,021,046, 0.25% - 6.13%, 8/15/24 - 2/15/52)	1,001,336	1,000,000
MUFG Securities EMEA PLC at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,069,347, 3.13% - 4.63%, 2/28/25 - 2/15/43)	1,000,400	1,000,000
Natixis SA at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,020,423, 2.38% - 4.75%, 2/15/37 - 11/15/42)	1,000,400	1,000,000
Norinchukin Bank at 4.85%, dated 4/25/23 due 5/2/23 (Collateralized by U.S. Treasury Obligations valued at $1,020,420, 2.75%, 5/31/29)	1,000,943	1,000,000
RBS Securities, Inc. at 4.8%, dated 4/28/23 due 5/1/23 (Collateralized by U.S. Treasury Obligations valued at $1,030,482, 2.50%, 2/15/45)	1,000,400	1,000,000
Societe Generale at 4.8%, dated 4/25/23 due 5/2/23 (Collateralized by U.S. Treasury Obligations valued at $1,020,837, 2.25%, 5/15/41)	1,000,933	1,000,000
TOTAL U.S. TREASURY REPURCHASE AGREEMENT (Cost $14,000,000)		14,000,000

TOTAL INVESTMENT IN SECURITIES - 96.0% (Cost $96,153,547)	96,153,547
NET OTHER ASSETS (LIABILITIES) - 4.0%	4,034,681
NET ASSETS - 100.0%	100,188,228

Legend

(a)	Yield represents either the annualized yield at the date of purchase, or the stated coupon rate, or, for floating and adjustable rate securities, the rate at period end.

(b)	Amount is stated in United States dollars unless otherwise noted.

(c)	Coupon rates for floating and adjustable rate securities reflect the rates in effect at period end.

(d)	Coupon is indexed to a floating interest rate which may be multiplied by a specified factor and/or subject to caps or floors.

(e)	The maturity amount is based on the rate at period end.

Investment Valuation

Other Information
# Additional information on each counterparty to the repurchase agreement is as follows:
Repurchase Agreement / Counterparty	Value ($)
$30,075,000 due 5/01/23 at 4.80%
BNY Mellon Capital Markets LLC	155,000
Bank of America, N.A.	447,000
BofA Securities, Inc.	310,000
Citigroup Global Markets, Inc.	310,000
Nomura Securities International	26,000,000
RBC Dominion Securities, Inc.	372,000
Sumitomo Mitsui Banking Corp.	1,736,000
Wells Fargo Securities LLC	745,000
	30,075,000

Statement of Assets and Liabilities
				April 30, 2023

Assets
Investment in securities, at value (including repurchase agreements of $64,575,000) - See accompanying schedule Unaffiliated issuers (cost $96,153,547):			$	96,153,547
Cash				1,000,151
Receivable for fund shares sold				7,990,597
Interest receivable				236,111
Total assets				105,380,406
Liabilities
Payable for fund shares redeemed	$	5,061,640
Distributions payable		130,538
Total Liabilities				5,192,178
Net Assets			$	100,188,228
Net Assets consist of:
Paid in capital			$	100,187,097
Total accumulated earnings (loss)				1,131
Net Assets			$	100,188,228
Net Asset Value , offering price and redemption price per share ($100,188,228 ÷ 100,183,180 shares)			$	1.00

Statement of Operations
				Year ended April 30, 2023
Investment Income
Interest			$	2,929,839
Expenses
Independent trustees' fees and expenses	$	335
Total Expenses				335
Net Investment income (loss)				2,929,504
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment Securities:
Unaffiliated issuers		(151)
Total net realized gain (loss)				(151)
Net increase in net assets resulting from operations			$	2,929,353

Statement of Changes in Net Assets

		Year ended April 30, 2023		Year ended April 30, 2022
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$	2,929,504	$	105,483
Net realized gain (loss)		(151)		19
Net increase in net assets resulting from operations		2,929,353		105,502
Distributions to shareholders		(2,928,222)		(103,717)
Share transactions
Proceeds from sales of shares		3,537,387,735		4,525,434,007
Reinvestment of distributions		1,972,006		71,753
Cost of shares redeemed		(3,555,577,849)		(4,508,081,749)
Net increase (decrease) in net assets and shares resulting from share transactions		(16,218,108)		17,424,011
Total increase (decrease) in net assets		(16,216,977)		17,425,796

Net Assets
Beginning of period		116,405,205		98,979,409
End of period	$	100,188,228	$	116,405,205

Other Information
Shares
Sold		3,537,387,735		4,525,434,007
Issued in reinvestment of distributions		1,972,006		71,753
Redeemed		(3,555,577,849)		(4,508,081,749)
Net increase (decrease)		(16,218,108)		17,424,011

Financial Highlights

Fidelity Flex® Government Money Market Fund

Years ended April 30,		2023		2022		2021		2020		2019
Selected Per-Share Data
Net asset value, beginning of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Income from Investment Operations
Net investment income (loss) A		.031		.001		.002		.018		.022
Net realized and unrealized gain (loss)		- B		- B		(.001)		- B		- B
Total from investment operations		.031		.001		.001		.018		.022
Distributions from net investment income		(.031)		(.001)		(.001)		(.018)		(.022)
Total distributions		(.031)		(.001)		(.001)		(.018)		(.022)
Net asset value, end of period	$	1.00	$	1.00	$	1.00	$	1.00	$	1.00
Total Return C		3.17%		.10%		.15%		1.81%		2.22%
Ratios to Average Net Assets A,D,E
Expenses before reductions F		-%		-%		-%		-%		-%
Expenses net of fee waivers, if any F		-%		-%		-%		-%		-%
Expenses net of all reductions F		-%		-%		-%		-%		-%
Net investment income (loss)		3.15%		.10%		.14%		1.64%		2.14%
Supplemental Data
Net assets, end of period (000 omitted)	$	100,188	$	116,405	$	98,979	$	50,942	$	22,044

B Amount represents less than $.0005 per share.

C Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

D Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses.

F Amount represents less than .005%.

For the period ended April 30, 2023

1. Organization.

Fidelity Flex Government Money Market Fund (the Fund) is a fund of Fidelity Hereford Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Share transactions on the Statement of Changes in Net Assets may contain exchanges between affiliated funds. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Delaware statutory trust. The Fund is available only to certain fee-based accounts and advisory programs offered by Fidelity.

2. Significant Accounting Policies.

Investment Valuation. The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Distributions are declared and recorded daily and paid monthly from net investment income. Distributions from realized gains, if any, are declared and recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from GAAP. In addition, the Fund claimed a portion of the payment made to redeeming shareholders as a distribution for income tax purposes.

Book-tax differences are primarily due to capital loss carryforwards.

As of period end, the cost and unrealized appreciation (depreciation) in securities for federal income tax purposes were as follows:

Gross unrealized appreciation	$-
Gross unrealized depreciation	-
Net unrealized appreciation (depreciation)	$-
Tax Cost	$96,153,547

The tax-based components of distributable earnings as of period end were as follows:

Undistributed ordinary income	$1,283
Capital loss carryforward	$(152)
Net unrealized appreciation (depreciation) on securities and other investments	$-

Short-term	$(-)
Long-term	(152)
Total capital loss carryforward	$(152)

The tax character of distributions paid was as follows:

	April 30, 2023	April 30, 2022
Ordinary Income	$2,928,222	$ 103,717

Repurchase Agreements. Pursuant to an Exemptive Order issued by the Securities and Exchange Commission, funds and other registered investment companies having management contracts with Fidelity Management and Research Company LLC, or its affiliates are permitted to transfer uninvested cash balances into joint trading accounts which are then invested in repurchase agreements. Funds may also invest directly with institutions in repurchase agreements. Repurchase agreements may be collateralized by cash or government securities. Upon settlement date, collateral is held in segregated accounts with custodian banks and may be obtained in the event of a default of the counterparty. The collateral balance is monitored on a daily basis to ensure it is at least equal to the principal amount of the repurchase agreement (including accrued interest). In the event of a default by the counterparty, realization of the collateral proceeds could be delayed, during which time the value of the collateral may decline.

3. Fees and Other Transactions with Affiliates.

Management Fee. Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services and the Fund does not pay any fees for these services. Under the management contract, the investment adviser or an affiliate pays all other expenses of the Fund, excluding fees and expenses of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses.

4. Other.

5. Risk and Uncertainties.

Report of Independent Registered Public Accounting Firm

To the Board of Trustees of Fidelity Hereford Street Trust and Shareholders of Fidelity Flex Government Money Market Fund

Opinion on the Financial Statements

We have audited the accompanying statement of assets and liabilities, including the schedule of investments, of Fidelity Flex Government Money Market Fund (one of the funds constituting Fidelity Hereford Street Trust, referred to hereafter as the "Fund") as of April 30, 2023, the related statement of operations for the year ended April 30, 2023, the statement of changes in net assets for each of the two years in the period ended April 30, 2023, including the related notes, and the financial highlights for each of the five years in the period ended April 30, 2023 (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Fund as of April 30, 2023, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period ended April 30, 2023 and the financial highlights for each of the five years in the period ended April 30, 2023 in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. Our procedures included confirmation of securities owned as of April 30, 2023 by correspondence with the custodians and brokers. We believe that our audits provide a reasonable basis for our opinion.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts

June 12, 2023

We have served as the auditor of one or more investment companies in the Fidelity group of funds since 1932.

Management's Discussion of Fund Performance

TRUSTEES AND OFFICERS

The fund's Statement of Additional Information (SAI) includes more information about the Trustees. To request a free copy, call Fidelity at 1-800-544-3455 (for managed account clients) or 1-800-835-5092 (for retirement plan participants).

Interested Trustees*:

Correspondence intended for a Trustee who is an interested person may be sent to Fidelity Investments, 245 Summer Street, Boston, Massachusetts 02210.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Abigail P. Johnson (1961)

Year of Election or Appointment: 2009

Trustee

Chairman of the Board of Trustees

Jennifer Toolin McAuliffe (1959)

Year of Election or Appointment: 2016

Trustee

* Determined to be an "Interested Trustee" by virtue of, among other things, his or her affiliation with the trust or various entities under common control with FMR.

Independent Trustees:

Correspondence intended for an Independent Trustee may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Year of Birth; Principal Occupations and Other Relevant Experience+

Elizabeth S. Acton (1951)

Year of Election or Appointment: 2013

Trustee

Ann E. Dunwoody (1953)

Year of Election or Appointment: 2018

Trustee

John Engler (1948)

Year of Election or Appointment: 2014

Trustee

Robert F. Gartland (1951)

Year of Election or Appointment: 2010

Trustee

Arthur E. Johnson (1947)

Year of Election or Appointment: 2008

Trustee

Michael E. Kenneally (1954)

Year of Election or Appointment: 2009

Trustee

Chairman of the Independent Trustees

Mark A. Murray (1954)

Year of Election or Appointment: 2016

Trustee

Advisory Board Members and Officers:

Name, Year of Birth; Principal Occupation

Laura M. Bishop (1961)

Year of Election or Appointment: 2022

Member of the Advisory Board

Robert W. Helm (1957)

Year of Election or Appointment: 2021

Member of the Advisory Board

Carol J. Zierhoffer (1960)

Year of Election or Appointment: 2023

Member of the Advisory Board

Heather Bonner (1977)

Year of Election or Appointment: 2023

Assistant Treasurer

Craig S. Brown (1977)

Year of Election or Appointment: 2019

Assistant Treasurer

John J. Burke III (1964)

Year of Election or Appointment: 2018

Chief Financial Officer

Margaret Carey (1973)

Year of Election or Appointment: 2023

Secretary and Chief Legal Officer (CLO)

David J. Carter (1973)

Year of Election or Appointment: 2020

Assistant Secretary

Jonathan Davis (1968)

Year of Election or Appointment: 2010

Assistant Treasurer

Laura M. Del Prato (1964)

Year of Election or Appointment: 2018

President and Treasurer

Christopher M. Gouveia (1973)

Year of Election or Appointment: 2023

Chief Compliance Officer

Colm A. Hogan (1973)

Year of Election or Appointment: 2016

Assistant Treasurer

Chris Maher (1972)

Year of Election or Appointment: 2013

Assistant Treasurer

Jamie Pagliocco (1964)

Year of Election or Appointment: 2020

Vice President

Brett Segaloff (1972)

Year of Election or Appointment: 2021

Anti-Money Laundering (AML) Officer

Stacie M. Smith (1974)

Year of Election or Appointment: 2013

Assistant Treasurer

Jim Wegmann (1979)

Year of Election or Appointment: 2021

Deputy Treasurer

Shareholder Expense Example

The Example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period (November 1, 2022 to April 30, 2023).

Actual Expenses

Hypothetical Example for Comparison Purposes

	Annualized Expense Ratio- A	Beginning Account Value November 1, 2022	Ending Account Value April 30, 2023	Expenses Paid During Period- C November 1, 2022 to April 30, 2023

Fidelity Flex® Government Money Market Fund	-%- D
Actual		$ 1,000	$ 1,021.90	$- E
Hypothetical- B		$ 1,000	$ 1,024.79	$- E

A Annualized expense ratio reflects expenses net of applicable fee waivers.

B 5% return per year before expenses

D Amount represents less than .005%.

E Amount represents less than $.005.

Distributions (Unaudited)

The dividend and capital gains distributions for the fund(s) are available on Fidelity.com or Institutional.Fidelity.com .

A total of 32.19% of the dividends distributed during the fiscal year was derived from interest on U.S. Government securities which is generally exempt from state income tax.

The fund designates $1,184,611 of distributions paid in the calendar year 2022, as qualifying to be taxed as interest-related dividends for nonresident alien shareholders.

The fund designates $2,928,222 of distributions paid during the fiscal year ended 2023 as qualifying to be taxed as section 163(j) interest dividends.

The fund will notify shareholders in January 2024 of amounts for use in preparing 2023 income tax returns.

1.9881599.106

ZGY-ANN-0623

Fidelity® Series Treasury Bill Index Fund

Annual Report

April 30, 2023

Contents

Performance

Investment Summary

Report of Independent Registered Public Accounting Firm

Liquidity Risk Management Program

You may also call 1-800-544-8544 to request a free copy of the proxy voting guidelines.

BLOOMBERG ® is a trademark and service mark of Bloomberg Finance L.P. and its affiliates (collectively "Bloomberg"). Bloomberg or Bloomberg's licensors own all proprietary rights in the Bloomberg Indices. Neither Bloomberg nor Bloomberg's licensors approves or endorses this material, or guarantees the accuracy or completeness of any information herein, or makes any warranty, express or implied, as to the results to be obtained therefrom and, to the maximum extent allowed by law, neither shall have any liability or responsibility for injury or damages arising in connection therewith.

Standard & Poor's, S&P and S&P 500 are registered service marks of The McGraw-Hill Companies, Inc. and have been licensed for use by Fidelity Distributors Corporation.

Other third-party marks appearing herein are the property of their respective owners.

NOT FDIC INSURED •MAY LOSE VALUE •NO BANK GUARANTEE

Neither the Fund nor Fidelity Distributors Corporation is a bank.

Performance: The Bottom Line

Average annual total return reflects the change in the value of an investment, assuming reinvestment of distributions from dividend income and capital gains (the profits earned upon the sale of securities that have grown in value, if any) and assuming a constant rate of performance each year. The hypothetical investment and the average annual total returns do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares. During periods of reimbursement by Fidelity, a fund's total return will be greater than it would be had the reimbursement not occurred. How a fund did yesterday is no guarantee of how it will do tomorrow.

Average Annual Total Returns

Periods ended April 30, 2023	Past 1 year	Life of Fund A
Fidelity® Series Treasury Bill Index Fund	2.78%	1.46%

A From August 17, 2018

$10,000 Over Life of Fund

Let's say hypothetically that $10,000 was invested in Fidelity® Series Treasury Bill Index Fund, on August 17, 2018, when the fund started.

The chart shows how the value of your investment would have changed, and also shows how the Bloomberg U.S. 3-6 Month Treasury Bill Index performed over the same period.

Management's Discussion of Fund Performance

Market Recap:

U.S. taxable investment-grade bonds returned -0.43% for the 12 months ending April 30, 2023, according to the Bloomberg U.S. Aggregate Bond Index. The first half of the 12-month period saw a continuation of the notable bond market downturn that began in early 2022, when the U.S. Federal Reserve, faced with persistent inflationary pressure, began an aggressive series of interest rate hikes to combat it. At the same time, the Fed tapered the stimulative, large-scale asset purchases it had dramatically expanded in 2020 amid the COVID-19 pandemic. The actions helped push nominal and real (inflation-adjusted) U.S. bond yields to their highest level in more than a decade. Bond prices, which move inversely to yields, fell sharply through October, and credit spreads widened, as investors demanded more yield for buying corporate debt and other credit-sensitive assets. In November, the bond market staged a broad rally (+3.68%) when comments by Fed Chair Jerome Powell pointed to a slowdown in the size of future rate hikes, and in December the Fed stepped down to a 0.50% rise after a series of 0.75% hikes, followed by 0.25% moves in February and March. To date, the central bank has raised its benchmark rate nine times, by a total of 4.75 percentage points. With the market anticipating the end of the Fed's hiking cycle later this year, the Aggregate index advanced 3.59% in the first four months of 2023. For the full 12 months, short-term bonds outperformed longer terms, while higher-risk assets like corporate bonds and asset-backed securities outpaced U.S. Treasuries. Meanwhile, residential and commercial mortgage-backed securities underperformed in the rising-rate environment.

Comments from Co-Portfolio Managers Brandon Bettencourt and Richard Munclinger:

For the fiscal year ending April 30, 2023, the fund returned 2.78%, roughly in line, net of fees, with the 2.81% result of the benchmark, the Bloomberg 3-6 Month Treasury Bill Index. This result met our goal of producing monthly returns, before expenses, that closely matched the benchmark's returns. We used a method known as "stratified sampling," which matches the index's risk factors, but does not always hold all bonds in the exact proportions of the index. For much of the 12-month period, U.S. Treasury bills - short-term, government-backed debt instruments with maturities of one year or less - posted negative results as the U.S. Federal Reserve aggressively raised interest rates to fight inflation, which peaked in June and remained stubbornly high throughout the period. But Treasury bills saw solid gains in the first four months of 2023, as the market looked toward the potential end of the Fed's rate-hiking cycle, and the fixed income market began to recover from a historically difficult 2022.

The views expressed above reflect those of the portfolio manager(s) only through the end of the period as stated on the cover of this report and do not necessarily represent the views of Fidelity or any other person in the Fidelity organization. Any such views are subject to change at any time based upon market or other conditions and Fidelity disclaims any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for a Fidelity fund are based on numerous factors, may not be relied on as an indication of trading intent on behalf of any Fidelity fund.

Investment Summary April 30, 2023 (Unaudited)

Asset Allocation (% of Fund's net assets)

Showing Percentage of Net Assets

U.S. Government and Government Agency Obligations - 99.5%
	Principal Amount (a)	Value ($)
U.S. Treasury Obligations - 99.5%
U.S. Treasury Bills, yield at date of purchase:
0%:
8/22/23	52,500,000	51,679,955
8/29/23	52,500,000	51,630,990
4.71% to 5.05% 8/1/23 to 10/26/23	1,209,652,000	1,188,323,462
TOTAL U.S. GOVERNMENT AND GOVERNMENT AGENCY OBLIGATIONS (Cost $1,292,044,689)		1,291,634,407

Money Market Funds - 0.7%
	Shares	Value ($)
Fidelity Cash Central Fund 4.88% (b) (Cost $8,931,866)	8,930,080	8,931,866

TOTAL INVESTMENT IN SECURITIES - 100.2% (Cost $1,300,976,555)	1,300,566,273
NET OTHER ASSETS (LIABILITIES) - (0.2)%	(2,441,787)
NET ASSETS - 100.0%	1,298,124,486

Legend

(a)	Amount is stated in United States dollars unless otherwise noted.

(b)

Affiliated fund that is generally available only to investment companies and other accounts managed by Fidelity Investments. The rate quoted is the annualized seven-day yield of the fund at period end. A complete unaudited listing of the fund's holdings as of its most recent quarter end is available upon request. In addition, each Fidelity Central Fund's financial statements, which are not covered by the Fund's Report of Independent Registered Public Accounting Firm, are available on the SEC's website or upon request.

Affiliated Central Funds

Fiscal year to date information regarding the Fund's investments in Fidelity Central Funds, including the ownership percentage, is presented below.

Affiliate	Value, beginning of period ($)	Purchases ($)	Sales Proceeds ($)	Dividend Income ($)	Realized Gain (loss) ($)	Change in Unrealized appreciation (depreciation) ($)	Value, end of period ($)	% ownership, end of period
Fidelity Cash Central Fund 4.88%	506,214	249,973,384	241,547,732	250,881	-	-	8,931,866	0.0%
Total	506,214	249,973,384	241,547,732	250,881	-	-	8,931,866

Amounts in the dividend income column in the above table include any capital gain distributions from underlying funds, which are presented in the corresponding line item in the Statement of Operations, if applicable.

Amounts included in the purchases and sales proceeds columns may include in-kind transactions, if applicable.

Investment Valuation

The following is a summary of the inputs used, as of April 30, 2023, involving the Fund's assets and liabilities carried at fair value. The inputs or methodology used for valuing securities may not be an indication of the risk associated with investing in those securities. For more information on valuation inputs, and their aggregation into the levels used below, please refer to the Investment Valuation section in the accompanying Notes to Financial Statements.

Valuation Inputs at Reporting Date:
Description	Total ($)	Level 1 ($)	Level 2 ($)	Level 3 ($)
Investments in Securities:

U.S. Government and Government Agency Obligations	1,291,634,407	-	1,291,634,407	-

Money Market Funds	8,931,866	8,931,866	-	-
Total Investments in Securities:	1,300,566,273	8,931,866	1,291,634,407	-

Statement of Assets and Liabilities
				April 30, 2023

Assets
Investment in securities, at value - See accompanying schedule:
Unaffiliated issuers (cost $1,292,044,689)	$	1,291,634,407
Fidelity Central Funds (cost $8,931,866)		8,931,866


Total Investment in Securities (cost $1,300,976,555)			$	1,300,566,273
Receivable for investments sold				516,306,556
Receivable for fund shares sold				22,478,487
Distributions receivable from Fidelity Central Funds				41,946
Total assets				1,839,393,262
Liabilities
Payable for investments purchased	$	541,135,319
Payable for fund shares redeemed		129,449
Other payables and accrued expenses		4,008
Total Liabilities				541,268,776
Net Assets			$	1,298,124,486
Net Assets consist of:
Paid in capital			$	1,306,492,204
Total accumulated earnings (loss)				(8,367,718)
Net Assets			$	1,298,124,486
Net Asset Value , offering price and redemption price per share ($1,298,124,486 ÷ 130,574,685 shares)			$	9.94

Statement of Operations
				Year ended April 30, 2023
Investment Income
Interest			$	36,724,484
Income from Fidelity Central Funds				250,881
Total Income				36,975,365
Expenses
Custodian fees and expenses	$	10,761
Independent trustees' fees and expenses		4,201
Total expenses before reductions		14,962
Expense reductions		(218)
Total expenses after reductions				14,744
Net Investment income (loss)				36,960,621
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment Securities:
Unaffiliated issuers		(5,793,880)
Total net realized gain (loss)				(5,793,880)
Change in net unrealized appreciation (depreciation) on investment securities				372,355
Net gain (loss)				(5,421,525)
Net increase (decrease) in net assets resulting from operations			$	31,539,096

Statement of Changes in Net Assets

		Year ended April 30, 2023		Year ended April 30, 2022
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$	36,960,621	$	3,082,388
Net realized gain (loss)		(5,793,880)		(2,011,309)
Change in net unrealized appreciation (depreciation)		372,355		(854,283)
Net increase (decrease) in net assets resulting from operations		31,539,096		216,796
Distributions to shareholders		(36,902,734)		(3,435,494)
Share transactions
Proceeds from sales of shares		687,602,491		956,901,033
Reinvestment of distributions		36,339,394		3,435,372
Cost of shares redeemed		(799,464,253)		(3,024,384,770)
Net increase (decrease) in net assets resulting from share transactions		(75,522,368)		(2,064,048,365)
Total increase (decrease) in net assets		(80,886,006)		(2,067,267,063)

Net Assets
Beginning of period		1,379,010,492		3,446,277,555
End of period	$	1,298,124,486	$	1,379,010,492

Other Information
Shares
Sold		69,090,565		95,697,239
Issued in reinvestment of distributions		3,651,949		343,736
Redeemed		(80,193,769)		(302,539,119)
Net increase (decrease)		(7,451,255)		(206,498,144)

Financial Highlights

Fidelity® Series Treasury Bill Index Fund

Years ended April 30,		2023		2022		2021		2020		2019 A
Selected Per-Share Data
Net asset value, beginning of period	$	9.99	$	10.00	$	10.03	$	9.98	$	10.00
Income from Investment Operations
Net investment income (loss) B,C		.327		.010		.011		.169		.166
Net realized and unrealized gain (loss)		(.054)		(.005)		.002		.062		(.005)
Total from investment operations		.273		.005		.013		.231		.161
Distributions from net investment income		(.323)		(.014)		(.012)		(.175)		(.181)
Distributions from net realized gain		-		(.001)		(.031)		(.006)		-
Total distributions		(.323)		(.015)		(.043)		(.181)		(.181)
Net asset value, end of period	$	9.94	$	9.99	$	10.00	$	10.03	$	9.98
Total Return D,E		2.78%		.05%		.13%		2.34%		1.62%
Ratios to Average Net Assets C,F,G
Expenses before reductions H		-%		-%		-%		-%		-% I
Expenses net of fee waivers, if any H		-%		-%		-%		-%		-% I
Expenses net of all reductions H		-%		-%		-%		-%		-% I
Net investment income (loss)		3.28%		.10%		.11%		1.69%		2.36% I
Supplemental Data
Net assets, end of period (000 omitted)	$	1,298,124	$	1,379,010	$	3,446,278	$	2,211,901	$	927,431
Portfolio turnover rate		-%		-%		-%		-%		-%

A For the period August 17, 2018 (commencement of operations) through April 30, 2019.

B Calculated based on average shares outstanding during the period.

C Net investment income (loss) is affected by the timing of the declaration of dividends by any underlying mutual funds or exchange-traded funds (ETFs). Net investment income (loss) of any mutual funds or ETFs is not included in the Fund's net investment income (loss) ratio.

D Total returns for periods of less than one year are not annualized.

E Total returns would have been lower if certain expenses had not been reduced during the applicable periods shown.

F Fees and expenses of any underlying mutual funds or exchange-traded funds (ETFs) are not included in the Fund's expense ratio. The Fund indirectly bears its proportionate share of these expenses. For additional expense information related to investments in Fidelity Central Funds, please refer to the "Investments in Fidelity Central Funds" note found in the Notes to Financial Statements section of the most recent Annual or Semi-Annual report.

H Amount represents less than .005%.

I Annualized.

For the period ended April 30, 2023

1. Organization.

Fidelity Series Treasury Bill Index Fund (the Fund) is a fund of Fidelity Hereford Street Trust (the Trust) and is authorized to issue an unlimited number of shares. Shares are offered only to certain other Fidelity funds, Fidelity managed 529 plans, and Fidelity managed collective investment trusts. The Trust is registered under the Investment Company Act of 1940, as amended (the 1940 Act), as an open-end management investment company organized as a Delaware statutory trust.

2. Investments in Fidelity Central Funds.

Funds may invest in Fidelity Central Funds, which are open-end investment companies generally available only to other investment companies and accounts managed by the investment adviser and its affiliates. The Schedule of Investments lists any Fidelity Central Funds held as an investment as of period end, but does not include the underlying holdings of each Fidelity Central Fund. An investing fund indirectly bears its proportionate share of the expenses of the underlying Fidelity Central Funds.

Based on its investment objective, each Fidelity Central Fund may invest or participate in various investment vehicles or strategies that are similar to those of the investing fund. These strategies are consistent with the investment objectives of the investing fund and may involve certain economic risks which may cause a decline in value of each of the Fidelity Central Funds and thus a decline in the value of the investing fund.

Fidelity Central Fund	Investment Manager	Investment Objective	Investment Practices	Expense Ratio A
Fidelity Money Market Central Funds	Fidelity Management & Research Company LLC (FMR)	Each fund seeks to obtain a high level of current income consistent with the preservation of capital and liquidity.	Short-term Investments	Less than .005%

A Expenses expressed as a percentage of average net assets and are as of each underlying Central Fund's most recent annual or semi-annual shareholder report.

A complete unaudited list of holdings for each Fidelity Central Fund is available upon request or at the Securities and Exchange Commission website at www.sec.gov. In addition, the financial statements of the Fidelity Central Funds which contain the significant accounting policies (including investment valuation policies) of those funds, and are not covered by the Report of Independent Registered Public Accounting Firm, are available on the Securities and Exchange Commission website or upon request.

3. Significant Accounting Policies.

Investment Valuation. Investments are valued as of 4:00 p.m. Eastern time on the last calendar day of the period. The Board of Trustees (the Board) has designated the Fund's investment adviser as the valuation designee responsible for the fair valuation function and performing fair value determinations as needed. The investment adviser has established a Fair Value Committee (the Committee) to carry out the day-to-day fair valuation responsibilities and has adopted policies and procedures to govern the fair valuation process and the activities of the Committee. In accordance with these fair valuation policies and procedures, which have been approved by the Board, the Fund attempts to obtain prices from one or more third party pricing services or brokers to value its investments. When current market prices, quotations or currency exchange rates are not readily available or reliable, investments will be fair valued in good faith by the Committee, in accordance with the policies and procedures. Factors used in determining fair value vary by investment type and may include market or investment specific events, transaction data, estimated cash flows, and market observations of comparable investments. The frequency that the fair valuation procedures are used cannot be predicted and they may be utilized to a significant extent. The Committee manages the Fund's fair valuation practices and maintains the fair valuation policies and procedures. The Fund's investment adviser reports to the Board information regarding the fair valuation process and related material matters.

The Fund categorizes the inputs to valuation techniques used to value its investments into a disclosure hierarchy consisting of three levels as shown below:

Level 1 - unadjusted quoted prices in active markets for identical investments

Level 2 - other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, etc.)

Level 3 - unobservable inputs (including the Fund's own assumptions based on the best information available)

Valuation techniques used to value the Fund's investments by major category are as follows:

Debt securities, including restricted securities, are valued based on evaluated prices received from third party pricing services or from brokers who make markets in such securities. U.S. government and government agency obligations are valued by pricing services who utilize matrix pricing which considers yield or price of bonds of comparable quality, coupon, maturity and type or by broker-supplied prices. When independent prices are unavailable or unreliable, debt securities may be valued utilizing pricing methodologies which consider similar factors that would be used by third party pricing services. Debt securities are generally categorized as Level 2 in the hierarchy but may be Level 3 depending on the circumstances.

Investments in open-end mutual funds, including the Fidelity Central Funds, are valued at their closing net asset value (NAV) each business day and are categorized as Level 1 in the hierarchy.

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The aggregate value of investments by input level as of April 30, 2023 is included at the end of the Fund's Schedule of Investments.

Investment Transactions and Income. For financial reporting purposes, the Fund's investment holdings and NAV include trades executed through the end of the last business day of the period. The NAV per share for processing shareholder transactions is calculated as of the close of business of the New York Stock Exchange (NYSE), normally 4:00 p.m. Eastern time and includes trades executed through the end of the prior business day. Gains and losses on securities sold are determined on the basis of identified cost. Income and capital gain distributions from Fidelity Central Funds, if any, are recorded on the ex-dividend date. Interest income is accrued as earned and includes coupon interest and amortization of premium and accretion of discount on debt securities as applicable.

Book-tax differences are primarily due to capital loss carryforwards.

As of period end, the cost and unrealized appreciation (depreciation) in securities, and derivatives if applicable, for federal income tax purposes were as follows:

Gross unrealized appreciation	$42
Gross unrealized depreciation	(410,324)
Net unrealized appreciation (depreciation)	$(410,282)
Tax Cost	$1,300,976,555

The tax-based components of distributable earnings as of period end were as follows:

Capital loss carryforward	$(7,805,165)
Net unrealized appreciation (depreciation) on securities and other investments	$(410,282)

Short-term	$(7,805,165)
Total capital loss carryforward	$(7,805,165)

The tax character of distributions paid was as follows:

	April 30, 2023	April 30, 2022
Ordinary Income	$36,902,734	$3,435,494

4. Fees and Other Transactions with Affiliates.

Management Fee. Fidelity Management & Research Company LLC (the investment adviser) and its affiliates provide the Fund with investment management related services for which the Fund does not pay a management fee. Under the management contract, the investment adviser or an affiliate pays all ordinary operating expenses of the Fund, except custody fees, fees and expenses of the independent Trustees, and certain miscellaneous expenses such as proxy and shareholder meeting expenses.

5. Committed Line of Credit.

Certain Funds participate with other funds managed by the investment adviser or an affiliate in a $4.25 billion credit facility (the "line of credit") to be utilized for temporary or emergency purposes to fund shareholder redemptions or for other short-term liquidity purposes. The commitment fees on the pro-rata portion of the line of credit are borne by the investment adviser. During the period, there were no borrowings on this line of credit.

6. Expense Reductions.

Through arrangements with the Fund's custodian and transfer agent, credits realized as a result of certain uninvested cash balances were used to reduce the Fund's expenses by $113 and $105, respectively.

7. Other.

At the end of the period, mutual funds and accounts managed by the investment adviser or its affiliates were the owners of record of all of the outstanding shares of the Fund.

8. Risk and Uncertainties.

Report of Independent Registered Public Accounting Firm

To the Board of Trustees of Fidelity Hereford Street Trust and the Shareholders of Fidelity Series Treasury Bill Index Fund:

Opinion on the Financial Statements and Financial Highlights

We have audited the accompanying statement of assets and liabilities of Fidelity Series Treasury Bill Index Fund (the "Fund"), a fund of Fidelity Hereford Street Trust, including the schedule of investments, as of April 30, 2023, the related statement of operations for the year then ended, the statement of changes in net assets for each of the two years in the period then ended, the financial highlights for each of the four years in the period then ended and for the period from August 17, 2018 (commencement of operations) through April 30, 2019, and the related notes. In our opinion, the financial statements and financial highlights present fairly, in all material respects, the financial position of the Fund as of April 30, 2023, and the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended, and the financial highlights for each of the four years in the period then ended and for the period from August 17, 2018 (commencement of operations) through April 30, 2019, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements and financial highlights are the responsibility of the Fund's management. Our responsibility is to express an opinion on the Fund's financial statements and financial highlights based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Fund in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements and financial highlights are free of material misstatement, whether due to error or fraud. The Fund is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Fund's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements and financial highlights, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements and financial highlights. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements and financial highlights. Our procedures included confirmation of securities owned as of April 30, 2023, by correspondence with the custodian and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

/s/ Deloitte & Touche LLP

Boston, Massachusetts

June 12, 2023

We have served as the auditor of one or more of the Fidelity investment companies since 1999.