UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-7139

Fidelity Hereford Street Trust
(Exact name of registrant as specified in charter)

82 Devonshire St., Boston, Massachusetts 02109
(Address of principal executive offices)       (Zip code)

Scott C. Goebel, Secretary

82 Devonshire St.

Boston, Massachusetts 02109
(Name and address of agent for service)

Registrant's telephone number, including area code: 617-563-7000

Date of fiscal year end:	April 30
Date of reporting period:	April 30, 2012

Item 1. Reports to Stockholders

Fidelity® Government Money 
Market Fund

Annual Report

April 30, 2012

(Fidelity Cover Art)

Contents

Shareholder Expense Example	(Click Here)	An example of shareholder expenses.
Investment Changes/Performance	(Click Here)	A summary of major shifts in the fund's investments over the past six months and one year.
Investments	(Click Here)	A complete list of the fund's investments.
Financial Statements	(Click Here)	Statements of assets and liabilities, operations, and changes in net assets, as well as financial highlights.
Notes	(Click Here)	Notes to the financial statements.
Report of Independent Registered Public Accounting Firm	(Click Here)
Trustees and Officers	(Click Here)
Distributions	(Click Here)

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov. 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.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.

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-Q. Forms N-Q are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-Q 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.advisor.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.

Annual Report

Shareholder Expense Example

As a shareholder of the Fund, you incur two types of costs: (1) transaction costs, and (2) ongoing costs, including management fees and other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of investing in the 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, 2011 to April 30, 2012).

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 under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. A small balance maintenance fee of $12.00 that is charged once a year may apply for certain accounts with a value of less than $2,000. This fee is not included in the table below. If it was, the estimate of expenses you paid during the period would be higher, and your ending account value lower, by this amount.

Hypothetical Example for Comparison Purposes

The second line of the accompanying table provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's 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. A small balance maintenance fee of $12.00 that is charged once a year may apply for certain accounts with a value of less than $2,000. This fee is not included in the table below. If it was, the estimate of expenses you paid during the period would be higher, and your ending account value lower, by this amount.

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.

Annual Report

Shareholder Expense Example - continued

	Annualized Expense Ratio	Beginning Account Value November 1, 2011	Ending Account Value April 30, 2012	Expenses Paid During Period* November 1, 2011 to April 30, 2012
Actual	.16%	$ 1,000.00	$ 1,000.05	$ .80 **
Hypothetical (5% return per year before expenses)		$ 1,000.00	$ 1,024.07	$ .81 **

* Expenses are equal to the Fund's annualized expense ratio, multiplied by the average account value over the period, multiplied by 182/366 (to reflect the one-half year period).

** If certain fees were not voluntarily waived by FMR or its affiliates during the period, the annualized expense ratio would have been .42% and the expenses paid in the actual and hypothetical examples above would have been $2.09 and $2.11, respectively.

Annual Report

Investment Changes/Performance (Unaudited)

Effective Maturity Diversification
Days	% of fund's investments 4/30/12	% of fund's investments 10/31/11	% of fund's investments 4/30/11
1 - 7	65.5	51.0	45.6
8 - 30	1.6	12.7	16.8
31 - 60	1.0	12.1	4.4
61 - 90	4.1	6.5	10.6
91 - 180	18.0	8.8	12.8
> 180	9.8	8.9	9.8

Effective maturity is determined in accordance with the requirements of Rule 2a-7 under the Investment Company Act of 1940.

Weighted Average Maturity
	4/30/12	10/31/11	4/30/11
Fidelity Government Money Market Fund	54 Days	53 Days	53 Days
Government Retail Money Market Funds Average *	48 Days	46 Days	46 Days

This is a weighted average of all the maturities of the securities held in a fund. Weighted Average Maturity (WAM) can be used as a measure of sensitivity to interest rate changes and market changes. Generally, the longer the maturity, the greater the sensitivity to such changes. WAM is based on the dollar-weighted average length of time until principal payments must be paid. Depending on the types of securities held in a fund, certain maturity shortening devices (e.g., demand features, interest rate resets, and call options) may be taken into account when calculating the WAM.

Weighted Average Life
	4/30/12	10/31/11	4/30/11
Fidelity Government Money Market Fund	58 Days	68 Days	99 Days

Weighted Average Life (WAL) is the weighted average of the life of the securities held in a fund or portfolio and can be used as a measure of sensitivity to changes in liquidity and/or credit risk. Generally, the higher the value, the greater the sensitivity. WAL is based on the dollar-weighted average length of time until 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. The difference between WAM and WAL is that WAM takes into account interest rate resets and WAL does not. WAL for money market funds is not the same as WAL of a mortgage- or asset-backed security.

Asset Allocation (% of fund's net assets)
As of April 30, 2012		As of October 31, 2011
	Treasury Debt 12.1%		Treasury Debt 10.5%
	Government Agency Debt † 22.8%		Government Agency Debt † 44.1%
	Repurchase Agreements 63.6%		Repurchase Agreements 46.2%
	Net Other Assets (Liabilities) 1.5%		Net Other Assets (Liabilities) ** (0.8)%

* Source: iMoneyNet, Inc.

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

^† Includes Federal Financing Bank Supported Student Loan Short-Term Notes.

Current and Historical Seven-Day Yields

	4/30/12	1/31/12	11/1/11	8/2/11	5/3/11
Fidelity Government Money Market Fund	0.01%	0.01%	0.01%	0.01%	0.01%

Yield refers to the income paid by the fund over a given period. Yields for money market funds are usually for seven-day periods, as they are here, though they are expressed as annual percentage rates. 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, 2012, the most recent period shown in the table, would have been -0.26%.

Annual Report

Investments April 30, 2012

Showing Percentage of Net Assets

Treasury Debt - 12.1%
		Yield (a)	Principal Amount	Value
U.S. Treasury Obligations - 12.1%
U.S. Treasury Bills
	9/13/12 to 2/7/13	0.12 to 0.15%	$ 123,880,000	$ 123,802,087
U.S. Treasury Notes
	5/15/12 to 2/28/13	0.07 to 0.21	217,000,000	218,512,721
TOTAL TREASURY DEBT				342,314,808
Government Agency Debt - 22.8%
Federal Agencies - 18.4%
Fannie Mae
	5/18/12 to 12/28/12	0.15 to 0.27 (c)	41,000,000	41,526,197
Federal Farm Credit Bank
	11/29/12 to 8/26/13	0.18 to 0.35 (c)	19,000,000	19,043,757
Federal Home Loan Bank
	5/1/12 to 2/27/13	0.09 to 0.41 (c)	407,023,333	407,074,850
Freddie Mac
	8/10/12 to 12/28/12	0.10 to 0.20 (c)	52,744,000	52,863,715
				520,508,519
Other Government Related - 4.4%
Straight-A Funding LLC (Liquidity Facility Federal Financing Bank)
	5/14/12	0.18 (b)	2,000,000	1,999,920
	7/6/12	0.18 (b)	4,000,000	3,998,760
	7/11/12	0.18 (b)	9,000,000	8,997,030
	7/12/12	0.18 (b)	5,000,000	4,998,275
	7/12/12	0.18 (b)	2,000,000	1,999,310
	7/13/12	0.18 (b)	2,000,000	1,999,300
	7/16/12	0.18 (b)	8,000,000	7,997,160
	7/23/12	0.18 (b)	13,000,000	12,994,930
	7/23/12	0.18 (b)	42,000,000	41,983,620
	7/26/12	0.18 (b)	10,000,000	9,995,850
	7/30/12	0.18 (b)	28,000,000	27,988,100
				124,952,255
TOTAL GOVERNMENT AGENCY DEBT				645,460,774

Government Agency Repurchase Agreement - 63.6%
	Maturity Amount		Value
In a joint trading account at 0.23% dated 4/30/12 due 5/1/12 (Collateralized by U.S. Government Obligations) #	$ 1,512,470,502		$ 1,512,461,000
With:
Barclays Capital, Inc. at:
0.19%, dated 3/16/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $6,121,486, 4% - 6.5%, 3/1/26 - 4/1/38)	6,001,932		6,000,000
0.2%, dated:
3/22/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $6,121,360, 3% - 6.5%, 11/1/26 - 2/1/39)	6,003,000		6,000,000
3/23/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $3,064,225, 5%, 9/1/40)	3,001,500		3,000,000
4/12/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $17,341,830, 3% - 7%, 11/1/21 - 11/1/41)	17,003,022		17,000,000
Citibank NA at 0.13%, dated 4/24/12 due 5/1/12 (Collateralized by U.S. Government Obligations valued at $23,460,594, 4%, 3/20/42)	23,000,581		23,000,000
Credit Suisse Securities (USA) LLC at:
0.13%, dated 4/24/12 due 5/1/12 (Collateralized by U.S. Government Obligations valued at $16,320,780, 5%, 7/1/35)	16,000,404		16,000,000
0.19%, dated 4/30/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $15,300,846, 4.5% - 6%, 10/1/34 - 5/1/41)	15,000,554		15,000,000
ING Financial Markets LLC at:
0.17%, dated 4/23/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $12,360,410, 3.5% - 6%, 3/15/34 - 1/25/42)	12,001,700		12,000,000
0.2%, dated:
4/9/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $5,150,639, 4% - 4.5%, 2/25/40 - 9/15/41)	5,000,861		5,000,000
4/16/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $6,185,180, 1.88% - 6%, 11/15/23 - 10/1/41)	6,001,000		6,000,000
RBC Capital Markets Corp. at 0.18%, dated 4/26/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $36,121,734, 2.5% - 4%, 5/25/30 - 12/25/41)	35,005,075		35,000,000
UBS Securities LLC at:
0.13%, dated 4/24/12 due 5/1/12 (Collateralized by U.S. Government Obligations valued at $8,160,207, 3%, 10/1/26)	8,000,202		8,000,000
Government Agency Repurchase Agreement - continued
	Maturity Amount		Value
With: - continued
UBS Securities LLC at:
0.18%, dated 4/30/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $111,180,557, 3.5%, 2/1/26 - 2/1/42)	$ 109,003,815		$ 109,000,000
0.2%, dated 4/25/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $24,480,816, 3%, 10/1/26)	24,004,000		24,000,000
TOTAL GOVERNMENT AGENCY REPURCHASE AGREEMENT		1,797,461,000
TOTAL INVESTMENT PORTFOLIO - 98.5% (Cost $2,785,236,582)		2,785,236,582
NET OTHER ASSETS (LIABILITIES) - 1.5%		41,048,750
NET ASSETS - 100%		$ 2,826,285,332

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) The Federal Financing Bank (FFB), an instrumentality of the U.S. Government acting under the supervision of the Secretary of the Treasury, has entered into a Liquidity Loan Agreement with Straight-A Funding LLC (Issuer), pursuant to which the FFB has committed, subject to certain conditions, to provide financing to the Issuer to cover any payment deficiencies in respect of notes on their legal final maturity dates. At the end of the period, these securities amounted to $124,952,255, or 4.4% of net assets.

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

# Additional information on each counterparty to the repurchase agreement is as follows:

Repurchase Agreement / Counterparty	Value
$1,512,461,000 due 5/01/12 at 0.23%
Credit Agricole CIB New York Branch	$ 294,405,530
Mizuho Securities USA, Inc.	1,218,055,470
	$ 1,512,461,000

Other Information

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.

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 those securities. For more information on valuation inputs, please refer to the Security Valuation section in the accompanying Notes to Financial Statements.

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Statements

Statement of Assets and Liabilities

	April 30, 2012
Assets
Investment in securities, at value (including repurchase agreements of $1,797,461,000) - See accompanying schedule: Unaffiliated issuers (cost $2,785,236,582)		$ 2,785,236,582
Receivable for fund shares sold		108,517,179
Interest receivable		1,626,509
Total assets		2,895,380,270
Liabilities
Payable to custodian bank	$ 318
Payable for investments purchased	14,997,525
Payable for fund shares redeemed	53,751,461
Distributions payable	1,495
Accrued management fee	343,171
Other affiliated payables	968
Total liabilities		69,094,938
Net Assets		$ 2,826,285,332
Net Assets consist of:
Paid in capital		$ 2,826,285,338
Accumulated undistributed net realized gain (loss) on investments		(6)
Net Assets, for 2,826,160,892 shares outstanding		$ 2,826,285,332
Net Asset Value, offering price and redemption price per share ($2,826,285,332 ÷ 2,826,160,892 shares)		$ 1.00

See accompanying notes which are an integral part of the financial statements.

Annual Report

Statement of Operations

	Year ended April 30, 2012
Investment Income
Interest		$ 1,595,691
Expenses
Management fee	$ 3,920,025
Independent trustees' compensation	2,816
Interest	14
Total expenses before reductions	3,922,855
Expense reductions	(2,420,407)	1,502,448
Net investment income (loss)		93,243
Realized and Unrealized Gain (Loss) Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers		2,906
Net increase in net assets resulting from operations		$ 96,149

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Statements - continued

Statement of Changes in Net Assets

	Year ended April 30, 2012	Year ended April 30, 2011
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$ 93,243	$ 65,692
Net realized gain (loss)	2,906	703
Net increase in net assets resulting from operations	96,149	66,395
Distributions to shareholders from net investment income	(93,393)	(65,686)
Distributions to shareholders from net realized gain	-	(26,109)
Total distributions	(93,393)	(91,795)
Share transactions at net asset value of $1.00 per share Proceeds from sales of shares	5,391,974,626	274,613,869
Reinvestment of distributions	86,063	85,555
Cost of shares redeemed	(3,149,240,306)	(391,356,336)
Net increase (decrease) in net assets and shares resulting from share transactions	2,242,820,383	(116,656,912)
Total increase (decrease) in net assets	2,242,823,139	(116,682,312)
Net Assets
Beginning of period	583,462,193	700,144,505
End of period (including undistributed net investment income of $0 and distributions in excess of net investment income of $299, respectively)	$ 2,826,285,332	$ 583,462,193

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Highlights

Years ended April 30,	2012	2011	2010	2009	2008
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)	- D	- D	.001	.015	.042
Net realized and unrealized gain (loss) D	-	-	-	-	-
Total from investment operations	- D	- D	.001	.015	.042
Distributions from net investment income	- D	- D	(.001)	(.015)	(.042)
Distributions from net realized gain	-	- D	- D	-	-
Total distributions	- D	- D	(.001)	(.015)	(.042)
Net asset value, end of period	$ 1.00	$ 1.00	$ 1.00	$ 1.00	$ 1.00
Total Return A,B	.01%	.01%	.09%	1.48%	4.31%
Ratios to Average Net Assets C
Expenses before reductions	.42%	.42%	.42%	.45%	.42%
Expenses net of fee waivers, if any	.16%	.26%	.35%	.45%	.42%
Expenses net of all reductions	.16%	.26%	.35%	.44%	.41%
Net investment income (loss)	.01%	.01%	.10%	1.39%	4.02%
Supplemental Data
Net assets, end of period (000 omitted)	$ 2,826,285	$ 583,462	$ 700,145	$ 1,144,433	$ 837,409

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

^B Total returns do not include the effect of the account closeout fee.

^C Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed or waived or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements, waivers or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement and waivers but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^D Amount represents less than $.001 per share.

See accompanying notes which are an integral part of the financial statements.

Annual Report

Notes to Financial Statements

For the period ended April 30, 2012

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.

2. Significant Accounting Policies.

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 following summarizes the significant accounting policies of the Fund:

Security 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 - 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. Interest income includes coupon interest and amortization of premium and accretion of discount on debt securities.

Annual Report

2. Significant Accounting Policies - continued

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. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

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 income taxes is required. As of April 30, 2012, 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. A 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.

Dividends 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.

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. Temporary book-tax differences will reverse in a subsequent period.

Book-tax differences are primarily due to deferred trustees compensation and losses deferred due to wash sales.

The federal tax cost of investment securities and unrealized appreciation (depreciation) as of period end were as follows:

Gross unrealized appreciation	$ -
Gross unrealized depreciation	-
Net unrealized appreciation (depreciation) on securities and other investments	$ -
Tax Cost	$ 2,785,236,582

Annual Report

Notes to Financial Statements - continued

2. Significant Accounting Policies - continued

Income Tax Information and Distributions to Shareholders - continued

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

Undistributed ordinary income	$ 1,199
Net unrealized appreciation (depreciation)	$ -

The tax character of distributions paid was as follows:

	April 30, 2012	April 30, 2011
Ordinary Income	$ 93,393	$ 91,795

3. Operating Policies.

Repurchase Agreements. Fidelity Management & Research Company (FMR) has received an Exemptive Order from the Securities and Exchange Commission (the SEC) which permits the Fund and other affiliated entities of FMR to transfer uninvested cash balances into joint trading accounts which are then invested in repurchase agreements. The Fund may also invest directly with institutions in repurchase agreements. Repurchase agreements are collateralized by government or non-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 Fund monitors, on a daily basis, the value of the collateral 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.

Reverse Repurchase Agreements. To enhance its yield, the Fund may enter into reverse repurchase agreements whereby the Fund transfers securities to a counterparty who then agrees to transfer them back to the Fund at a future date and agreed upon price, reflecting a rate of interest below market rate. Securities sold under a reverse repurchase agreement, if any, are recorded as a liability in the accompanying Statement of Assets and Liabilities. The Fund receives cash proceeds, which are invested in other securities, and agrees to repay the proceeds plus any accrued interest in return for the same securities transferred. The Fund continues to receive interest payments on the transferred securities during the term of the reverse repurchase agreement. During the period that a reverse repurchase agreement is outstanding, the Fund identifies cash and liquid securities as segregated in its custodian records with a value at least equal to its obligation under the agreement. If the counterparty defaults on its obligation, because of

Annual Report

3. Operating Policies - continued

Reverse Repurchase Agreements - continued

insolvency or other reasons, the Fund could experience delays and costs in recovering the security or in gaining access to the collateral. The average balance during the period for which reverse repurchase agreements were outstanding subject to interest amounted to $2,110,722. The weighted average interest rate was .01% on such amounts. At period end, there were no reverse repurchase agreements outstanding.

4. Fees and Other Transactions with Affiliates.

Management Fee. FMR 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. FMR pays all other expenses, except the compensation of the independent Trustees and certain exceptions such as interest expense. The management fee paid to FMR by the Fund is reduced by an amount equal to the fees and expenses paid by the Fund to the independent Trustees.

5. Expense Reductions.

FMR or its affiliates voluntarily agreed to waive certain fees in order to maintain a minimum annualized yield of .01%. Such arrangements may be discontinued by FMR at any time. For the period, the amount of the waiver was $2,420,390.

In addition, through arrangements with the Fund's custodian, credits realized as a result of uninvested cash balances were used to reduce the Fund's management fee. During the period, these credits reduced the Fund's management fee by $17.

6. Other.

The 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, the Fund may also enter into contracts that provide general indemnifications. The Fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against the Fund. The risk of material loss from such claims is considered remote.

Annual Report

Report of Independent Registered Public Accounting Firm

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

In our opinion, the accompanying statement of assets and liabilities, including the schedule of investments, and the related statements of operations and of changes in net assets and the financial highlights present fairly, in all material respects, the financial position of Fidelity Government Money Market Fund (a fund of Fidelity Hereford Street Trust) at April 30, 2012, 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 five years in the period then ended, in conformity with accounting principles generally accepted in the United States of America. These financial statements and financial highlights (hereafter referred to as "financial statements") are the responsibility of the Fidelity Government Money Market Fund's management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits, which included confirmation of securities at April 30, 2012 by correspondence with the custodian and brokers, provide a reasonable basis for our opinion.

PricewaterhouseCoopers LLP

Boston, Massachusetts

June 6, 2012

Annual Report

Trustees and Officers

The Trustees and executive 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. Except for Mr. Curvey, each of the Trustees oversees 207 funds advised by FMR or an affiliate. Mr. Curvey oversees 435 funds advised by FMR or an affiliate.

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) (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. The executive officers hold office without limit in time, except that any officer 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.

Experience, Skills, Attributes, and Qualifications of the Fund's 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.

Annual Report

Trustees and Officers - continued

Board Structure and Oversight Function. Abigail P. Johnson is an interested person (as defined in the 1940 Act) 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. Kenneth L. Wolfe 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, and asset allocation funds and another Board oversees Fidelity's equity and high income funds. The asset allocation funds may invest in Fidelity funds that are overseen by such other Board. 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 FMR'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 Fund's Trustees."

Annual Report

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 each Trustee who is an interested person may be sent to Fidelity Investments, 82 Devonshire Street, Boston, Massachusetts 02109.

Name, Age; Principal Occupations and Other Relevant Experience+
Abigail P. Johnson (50)
	Year of Election or Appointment: 2009 Ms. Johnson is Trustee and Chairman of the Board of Trustees of certain Trusts. Ms. Johnson serves as President of Personal, Workplace and Institutional Services (2005-present). Ms. Johnson is Chairman and Director of FMR Co., Inc. (2011-present), Chairman and Director of FMR (2011-present), and the Vice Chairman and Director (2007-present) of FMR LLC. Previously, Ms. Johnson served as President and a Director of FMR (2001-2005), a Trustee of other investment companies advised by FMR, Fidelity Investments Money Management, Inc., 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.
James C. Curvey (76)
	Year of Election or Appointment: 2007 Mr. Curvey also serves as Trustee (2007-present) of other investment companies advised by FMR. Mr. Curvey is a Director of Fidelity Investments Money Management, Inc. (2009-present), Director of Fidelity Research & Analysis Co. (2009-present) and Director of FMR and FMR Co., Inc. (2007-present). Mr. Curvey is also Vice Chairman (2007-present) and Director of FMR LLC. In addition, Mr. Curvey serves as an Overseer for the Boston Symphony Orchestra and a member of the Trustees of Villanova University. Previously, Mr. Curvey was the Vice Chairman (2006-2007) and Director (2000-2007) of FMR Corp.

* Trustees have been determined to be "Interested Trustees" by virtue of, among other things, their affiliation with the trust or various entities under common control with FMR.

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

Independent Trustees:

Correspondence intended for each Independent Trustee (that is, the Trustees other than the Interested Trustees) may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Age; Principal Occupations and Other Relevant Experience+
Albert R. Gamper, Jr. (70)
	Year of Election or Appointment: 2006 Mr. Gamper is Vice Chairman of the Independent Trustees of the Fixed Income and Asset Allocation Funds (2011-present). Prior to his retirement in December 2004, Mr. Gamper served as Chairman of the Board of CIT Group Inc. (commercial finance). During his tenure with CIT Group Inc. Mr. Gamper served in numerous senior management positions, including Chairman (1987-1989; 1999-2001; 2002-2004), Chief Executive Officer (1987-2004), and President (2002-2003). Mr. Gamper currently serves as a member of the Board of Directors of Public Service Enterprise Group (utilities, 2000-present), a member of the Board of Trustees, Rutgers University (2004-present), and Chairman of the Board of Saint Barnabas Health Care System. Previously, Mr. Gamper served as Chairman of the Board of Governors, Rutgers University (2004-2007).
Robert F. Gartland (60)
	Year of Election or Appointment: 2010 Mr. Gartland is Chairman and an investor in Gartland and Mellina Group Corp. (consulting, 2009-present). Previously, Mr. Gartland served as a partner and investor of Vietnam Partners LLC (investments and consulting, 2008-2011). Prior to his retirement, Mr. Gartland held a variety of positions at Morgan Stanley (financial services, 1979-2007) including Managing Director (1987-2007).
Arthur E. Johnson (65)
	Year of Election or Appointment: 2008 Mr. Johnson serves as a member of the Board of Directors of Eaton Corporation (diversified power management, 2009-present), AGL Resources, Inc. (holding company, 2002-present) and Booz Allen Hamilton (management consulting, 2011-present). Prior to his retirement, Mr. Johnson served as Senior Vice President of Corporate Strategic Development of Lockheed Martin Corporation (defense contractor, 1999-2009). He previously served on the Board of Directors of IKON Office Solutions, Inc. (1999-2008) and Delta Airlines (2005-2007). Mr. Arthur E. Johnson is not related to Mr. Edward C. Johnson 3d or Ms. Abigail P. Johnson.
Michael E. Kenneally (58)
	Year of Election or Appointment: 2009 Previously, Mr. Kenneally served as a Member of the Advisory Board for certain Fidelity Fixed Income and Asset Allocation Funds (2008-2009). Prior to his retirement, Mr. Kenneally served as Chairman and Global Chief Executive Officer of Credit Suisse Asset Management (2003-2005). Mr. Kenneally was a Director of the Credit Suisse Funds (U.S. mutual funds, 2004-2008) and certain other closed-end funds (2004-2005) and was awarded the Chartered Financial Analyst (CFA) designation in 1991.
James H. Keyes (71)
	Year of Election or Appointment: 2007 Mr. Keyes serves as a member of the Boards of Navistar International Corporation (manufacture and sale of trucks, buses, and diesel engines, since 2002) and Pitney Bowes, Inc. (integrated mail, messaging, and document management solutions, since 1998). Prior to his retirement, Mr. Keyes served as Chairman and Chief Executive Officer of Johnson Controls (automotive, building, and energy, 1998-2002) and as a member of the Board of LSI Logic Corporation (semiconductor technologies, 1984-2008).
Marie L. Knowles (65)
	Year of Election or Appointment: 2001 Prior to Ms. Knowles' retirement in June 2000, she served as Executive Vice President and Chief Financial Officer of Atlantic Richfield Company (ARCO) (diversified energy, 1996-2000). From 1993 to 1996, she was a Senior Vice President of ARCO and President of ARCO Transportation Company. She served as a Director of ARCO from 1996 to 1998. Ms. Knowles currently serves as a Director and Chairman of the Audit Committee of McKesson Corporation (healthcare service, since 2002). Ms. Knowles is an Honorary Trustee of the Brookings Institution and a member of the Board of the Catalina Island Conservancy and of the Santa Catalina Island Company (2009-present). She also serves as a member of the Advisory Board for the School of Engineering of the University of Southern California and the Foundation Board of the School of Architecture at the University of Virginia (2007-present). Previously, Ms. Knowles served as a Director of Phelps Dodge Corporation (copper mining and manufacturing, 1994-2007).
Kenneth L. Wolfe (73)
	Year of Election or Appointment: 2005 Mr. Wolfe is Chairman of the Independent Trustees of the Fixed Income and Asset Allocation Funds (2008-present). Prior to his retirement, Mr. Wolfe served as Chairman and a Director (2007-2009) and Chairman and Chief Executive Officer (1994-2001) of Hershey Foods Corporation. He also served as a member of the Boards of Adelphia Communications Corporation (telecommunications, 2003-2006), Bausch & Lomb, Inc. (medical/pharmaceutical, 1993-2007), and Revlon, Inc. (personal care products, 2004-2009).

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

Annual Report

Executive Officers:

Correspondence intended for each executive officer may be sent to Fidelity Investments, 82 Devonshire Street, Boston, Massachusetts 02109.

Name, Age; Principal Occupation
John R. Hebble (53)
	Year of Election or Appointment: 2008 President and Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Hebble also serves as President (2011-present), Treasurer, and Chief Financial Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present), Assistant Treasurer of other Fidelity funds (2009-present) and is an employee of Fidelity Investments.
Robert P. Brown (48)
	Year of Election or Appointment: 2010 Vice President of Fidelity's Money Market Funds and Executive Vice President of Fidelity Investments Money Management, Inc. (2010-present). Mr. Brown also serves as President, Money Market Group of FMR (2010-present), Managing Director of Research, Director of Fidelity Management & Research (U.K.) Inc. (2008-present) and is an employee of Fidelity Investments.
Scott C. Goebel (44)
	Year of Election or Appointment: 2008 Secretary and Chief Legal Officer (CLO) of the Fidelity funds. Mr. Goebel also serves as Secretary of Fidelity Investments Money Management, Inc. (FIMM) (2010-present) and Fidelity Research and Analysis Company (FRAC) (2010-present); Secretary and CLO of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present); General Counsel, Secretary, and Senior Vice President of FMR (2008-present) and FMR Co., Inc. (2008-present); employed by FMR LLC or an affiliate (2001-present); Chief Legal Officer of Fidelity Management & Research (Hong Kong) Limited (2008-present) and Assistant Secretary of Fidelity Management & Research (Japan) Inc. (2008-present), and Fidelity Management & Research (U.K.) Inc. (2008-present). Previously, Mr. Goebel served as Assistant Secretary of FIMM (2008-2010), FRAC (2008-2010), and the Funds (2007-2008) and as Vice President and Secretary of Fidelity Distributors Corporation (FDC) (2005-2007).
David J. Carter (38)
	Year of Election or Appointment: 2010 Assistant Secretary of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Carter also serves as Vice President, Associate General Counsel (2010-present) and is an employee of Fidelity Investments (2005-present).
Elizabeth Paige Baumann (43)
	Year of Election or Appointment: 2012 Anti-Money Laundering (AML) Officer of the Fidelity funds. Ms. Baumann also serves as AML Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2012-present), Chief AML Officer of FMR LLC (2012-present), and is an employee of Fidelity Investments. Previously, Ms. Baumann served as Vice President and Deputy Anti-Money Laundering Officer (2007-2012).
Christine Reynolds (53)
	Year of Election or Appointment: 2008 Chief Financial Officer of the Fidelity funds. Ms. Reynolds became President of Fidelity Pricing and Cash Management Services (FPCMS) in August 2008. Ms. Reynolds served as Chief Operating Officer of FPCMS (2007-2008). Previously, Ms. Reynolds served as President, Treasurer, and Anti-Money Laundering officer of the Fidelity funds (2004-2007).
Michael H. Whitaker (44)
	Year of Election or Appointment: 2008 Chief Compliance Officer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Whitaker also serves as Chief Compliance Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present). Mr. Whitaker is an employee of Fidelity Investments (2007-present). Prior to joining Fidelity Investments, Mr. Whitaker worked at MFS Investment Management where he served as Senior Vice President and Chief Compliance Officer (2004-2006), and Assistant General Counsel.
Joseph F. Zambello (54)
	Year of Election or Appointment: 2011 Deputy Treasurer of the Fidelity funds. Mr. Zambello is an employee of Fidelity Investments. Previously, Mr. Zambello served as Vice President of FMR's Program Management Group (2009-2011) and Vice President of the Transfer Agent Oversight Group (2005-2009).
Stephanie J. Dorsey (42)
	Year of Election or Appointment: 2008 Deputy Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Ms. Dorsey also serves as Assistant Treasurer of other Fidelity funds (2010-present) and is an employee of Fidelity Investments (2008-present). Previously, Ms. Dorsey served as Treasurer (2004-2008) of the JPMorgan Mutual Funds and Vice President (2004-2008) of JPMorgan Chase Bank.
Adrien E. Deberghes (44)
	Year of Election or Appointment: 2010 Assistant Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Deberghes also serves as Vice President and Assistant Treasurer (2011-present) and Deputy Treasurer (2008-present) of other Fidelity funds, and is an employee of Fidelity Investments (2008-present). Previously, Mr. Deberghes served as Senior Vice President of Mutual Fund Administration at State Street Corporation (2007-2008), Senior Director of Mutual Fund Administration at Investors Bank & Trust (2005-2007), and Director of Finance for Dunkin' Brands (2000-2005).
Kenneth B. Robins (42)
	Year of Election or Appointment: 2009 Assistant Treasurer of the Fidelity Fixed Income and Asset Allocation Funds. Mr. Robins also serves as President and Treasurer of other Fidelity funds (2008-present; 2010-present) and is an employee of Fidelity Investments (2004-present). Previously, Mr. Robins served as Deputy Treasurer of the Fidelity funds (2005-2008) and Treasurer and Chief Financial Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2006-2008).
Gary W. Ryan (53)
	Year of Election or Appointment: 2005 Assistant Treasurer of the Fidelity funds. Mr. Ryan is an employee of Fidelity Investments. Previously, Mr. Ryan served as Vice President of Fund Reporting in Fidelity Pricing and Cash Management Services (FPCMS) (1999-2005).
Jonathan Davis (43)
	Year of Election or Appointment: 2010 Assistant Treasurer of the Fidelity funds. Mr. Davis is also Assistant Treasurer of Fidelity Rutland Square Trust II and Fidelity Commonwealth Trust II. Mr. Davis is an employee of Fidelity Investments. Previously, Mr. Davis served as Vice President and Associate General Counsel of FMR LLC (2003-2010).

Annual Report

Distributions (Unaudited)

A total of 33.04% 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 $50,953 of distributions paid during the period January 1, 2012 to April 30, 2012 as qualifying to be taxed as interest-related dividends for nonresident alien shareholders.

The fund will notify shareholders in January 2013 of amounts for use in preparing 2012 income tax returns.

Annual Report

Investment Adviser

Fidelity Management & Research Company
Boston, MA

Investment Sub-Advisers

Fidelity Investments
Money Management, Inc.

Fidelity Management & Research
(U.K.) Inc.

Fidelity Management & Research
(Hong Kong) Limited

Fidelity Management & Research
(Japan) Inc.

General Distributor

Fidelity Distributors Corporation

Boston, MA

Transfer and Service Agents

Fidelity Investments Institutional
Operations Company, Inc.

Boston, MA

Fidelity Service Company, Inc.

Boston, MA

Custodian

JPMorgan Chase Bank

New York, NY

The Fidelity Telephone Connection

Mutual Fund 24-Hour Service

Exchanges/Redemptions
and Account Assistance 1-800-544-6666

Product Information 1-800-544-6666

Retirement Accounts 1-800-544-4774 (8 a.m. - 9 p.m.)

TDD Service 1-800-544-0118
for the deaf and hearing impaired
(9 a.m. - 9 p.m. Eastern time)

Fidelity Automated Service
Telephone (FAST®)
1-800-544-5555

Automated line for quickest service

(Fidelity Investment logo)(registered trademark)
Corporate Headquarters
82 Devonshire St., Boston, MA 02109
www.fidelity.com

SPU-UANN-0612
1.784733.109

Fidelity®

U.S. Treasury
Money Market Fund

Annual Report

April 30, 2012

(Fidelity Cover Art)

Contents

Shareholder Expense Example	(Click Here)	An example of shareholder expenses.
Investment Changes/Performance	(Click Here)	A summary of major shifts in the fund's investments over the past six months and one year.
Investments	(Click Here)	A complete list of the fund's investments.
Financial Statements	(Click Here)	Statements of assets and liabilities, operations, and changes in net assets, as well as financial highlights.
Notes	(Click Here)	Notes to the financial statements.
Report of Independent Registered Public Accounting Firm	(Click Here)
Trustees and Officers	(Click Here)
Distributions	(Click Here)

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov. 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.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.

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-Q. Forms N-Q are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-Q 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.advisor.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.

Annual Report

Shareholder Expense Example

As a shareholder of the Fund, you incur two types of costs: (1) transaction costs, and (2) ongoing costs, including management fees and other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of investing in the 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, 2011 to April 30, 2012).

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 under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. A small balance maintenance fee of $12.00 that is charged once a year may apply for certain accounts with a value of less than $2,000. This fee is not included in the table below. If it was, the estimate of expenses you paid during the period would be higher, and your ending account value lower, by this amount.

Hypothetical Example for Comparison Purposes

The second line of the accompanying table provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's 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. A small balance maintenance fee of $12.00 that is charged once a year may apply for certain accounts with a value of less than $2,000. This fee is not included in the table below. If it was, the estimate of expenses you paid during the period would be higher, and your ending account value lower, by this amount.

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.

Annual Report

	Annualized Expense Ratio	Beginning Account Value November 1, 2011	Ending Account Value April 30, 2012	Expenses Paid During Period* November 1, 2011 to April 30, 2012
Actual	.05%	$ 1,000.00	$ 1,000.05	$ .25**
Hypothetical (5% return per year before expenses)		$ 1,000.00	$ 1,024.61	$ .25**

* Expenses are equal to the Fund's annualized expense ratio, multiplied by the average account value over the period, multiplied by 182/366 (to reflect the one-half year period).

** If certain fees were not voluntarily waived by FMR or its affiliates during the period, the annualized expense ratio for the U.S. Treasury Money Market Fund would have been 0.42% and the expenses paid in the actual and hypothetical examples above would have been $2.09 and $2.11, respectively.

Annual Report

Investment Changes/Performance (Unaudited)

Effective Maturity Diversification
Days	% of fund's investments 4/30/12	% of fund's investments 10/31/11	% of fund's investments 4/30/11
1 - 7	10.3	12.5	3.3
8 - 30	20.4	35.7	27.5
31 - 60	19.7	20.8	22.4
61 - 90	34.5	9.7	30.8
91 - 180	14.3	15.2	10.7
> 180	0.8	6.1	5.3

Effective maturity is determined in accordance with the requirements of Rule 2a-7 under the Investment Company Act of 1940.

Weighted Average Maturity
	4/30/12	10/31/11	4/30/11
Fidelity U.S. Treasury Money Market Fund	55 Days	51 Days	54 Days
Treasury Retail Money Market Funds Average *	50 Days	54 Days	51 Days

This is a weighted average of all the maturities of the securities held in a fund. Weighted Average Maturity (WAM) can be used as a measure of sensitivity to interest rate changes and market changes. Generally, the longer the maturity, the greater the sensitivity to such changes. WAM is based on the dollar-weighted average length of time until principal payments must be paid. Depending on the types of securities held in a fund, certain maturity shortening devices (e.g., demand features, interest rate resets, and call options) may be taken into account when calculating the WAM.

Weighted Average Life
	4/30/12	10/31/11	4/30/11
Fidelity U.S. Treasury Money Market Fund	55 Days	51 Days	54 Days

Weighted Average Life (WAL) is the weighted average of the life of the securities held in a fund or portfolio and can be used as a measure of sensitivity to changes in liquidity and/or credit risk. Generally, the higher the value, the greater the sensitivity. WAL is based on the dollar-weighted average length of time until 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. The difference between WAM and WAL is that WAM takes into account interest rate resets and WAL does not. WAL for money market funds is not the same as WAL of a mortgage- or asset-backed security.

Asset Allocation (% of fund's net assets)
As of April 30, 2012		As of October 31, 2011
	Treasury Debt 105.7%		Treasury Debt 109.8%
	Net Other Assets (Liabilities)** (5.7)%		Net Other Assets (Liabilities)** (9.8)%

* Source: iMoneyNet, Inc.

** Net Other Assets are not included in the pie chart

Annual Report

Current and Historical Seven-Day Yields

	4/30/12	1/31/12	11/1/11	8/2/11	5/3/11
Fidelity U.S. Treasury Money Market Fund	0.01%	0.01%	0.01%	0.01%	0.01%

Yield refers to the income paid by the fund over a given period. Yields for money market funds are usually for seven-day periods, as they are here, though they are expressed as annual percentage rates. Past performance is no guarantee of future results. Yield will vary and it's possible to lose money by 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, 2012, the most recent period shown in the table, would have been -0.34%.

Annual Report

Investments April 30, 2012

Showing Percentage of Net Assets

Treasury Debt - 105.7%
		Yield (a)	Principal Amount (000s)	Value (000s)
U.S. Treasury Obligations - 105.7%
U.S. Treasury Bills
	5/3/12 to 10/11/12	0.06 to 0.15%	$ 4,756,537	$ 4,755,924
U.S. Treasury Notes
	5/15/12 to 10/31/12	0.05 to 0.16	1,629,360	1,634,583

TOTAL INVESTMENT PORTFOLIO - 105.7% (Cost $6,390,507)		6,390,507
NET OTHER ASSETS (LIABILITIES) - (5.7)%		(346,973)
NET ASSETS - 100%	$ 6,043,534

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.

Other Information

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.

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 those securities. For more information on valuation inputs, please refer to the Security Valuation section in the accompanying Notes to Financial Statements.

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Statements

Statement of Assets and Liabilities

Amounts in thousands (except per-share amount)	April 30, 2012
Assets
Investment in securities, at value - See accompanying schedule: Unaffiliated issuers (cost $6,390,507)		$ 6,390,507
Receivable for fund shares sold		11,104
Interest receivable		7,866
Other receivables		4
Total assets		6,409,481
Liabilities
Payable for investments purchased	$ 349,912
Payable for fund shares redeemed	15,636
Distributions payable	5
Accrued management fee	392
Other affiliated payables	2
Total liabilities		365,947
Net Assets		$ 6,043,534
Net Assets consist of:
Paid in capital		$ 6,043,491
Accumulated undistributed net realized gain (loss) on investments		43
Net Assets, for 6,042,886 shares outstanding		$ 6,043,534
Net Asset Value, offering price and redemption price per share ($6,043,534 ÷ 6,042,886 shares)		$ 1.00

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Statements - continued

Statement of Operations

Amounts in thousands	Year ended April 30, 2012
Investment Income
Interest		$ 3,696
Expenses
Management fee	$ 25,173
Independent trustees' compensation	21
Total expenses before reductions	25,194
Expense reductions	(22,099)	3,095
Net investment income (loss)		601
Realized and Unrealized Gain (Loss) Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers		30
Net increase in net assets resulting from operations		$ 631

See accompanying notes which are an integral part of the financial statements.

Annual Report

Statement of Changes in Net Assets

Amounts in thousands	Year ended April 30, 2012	Year ended April 30, 2011
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$ 601	$ 499
Net realized gain (loss)	30	43
Net increase in net assets resulting from operations	631	542
Distributions to shareholders from net investment income	(601)	(499)
Share transactions at net asset value of $1.00 per share Proceeds from sales of shares	5,249,374	1,898,443
Reinvestment of distributions	544	462
Cost of shares redeemed	(3,928,864)	(2,372,891)
Net increase (decrease) in net assets and shares resulting from share transactions	1,321,054	(473,986)
Total increase (decrease) in net assets	1,321,084	(473,943)
Net Assets
Beginning of period	4,722,450	5,196,393
End of period	$ 6,043,534	$ 4,722,450

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Highlights

Years ended April 30,	2012	2011	2010	2009	2008
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)	- D	- D	- D	.007	.035
Net realized and unrealized gain (loss) D	-	-	-	-	-
Total from investment operations	- D	- D	- D	.007	.035
Distributions from net investment income	- D	- D	- D	(.007)	(.035)
Distributions from net realized gain	-	-	- D	-	-
Total distributions	- D	- D	- D	(.007)	(.035)
Net asset value, end of period	$ 1.00	$ 1.00	$ 1.00	$ 1.00	$ 1.00
Total Return A, B	.01%	.01%	.02%	.75%	3.59%
Ratios to Average Net Assets C
Expenses before reductions	.42%	.42%	.42%	.45%	.45%
Expenses net of fee waivers, if any	.05%	.17%	.27%	.45%	.45%
Expenses net of all reductions	.05%	.17%	.27%	.45%	.44%
Net investment income (loss)	.01%	.01%	.01%	.58%	3.21%
Supplemental Data
Net assets, end of period (in millions)	$ 6,044	$ 4,722	$ 5,196	$ 8,413	$ 4,786

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

^B Total returns do not include the effect of the account closeout fee.

^C Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed or waived or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements, waivers or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement and waivers but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^D Amount represents less than $.001 per share.

See accompanying notes which are an integral part of the financial statements.

Annual Report

Notes to Financial Statements

For the period ended April 30, 2012

(Amounts in thousands except percentages)

1. Organization.

Fidelity® U.S. Treasury 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.

2. Significant Accounting Policies.

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 following summarizes the significant accounting policies of the Fund:

Security 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 - 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. Interest income includes coupon interest and amortization of premium and accretion of discount on debt securities.

Annual Report

Notes to Financial Statements - continued

(Amounts in thousands except percentages)

2. Significant Accounting Policies - continued

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. Expense estimates are accrued in the period to which they relate and adjustments are made when actual amounts are known.

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 income taxes is required. As of April 30, 2012, 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. A 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.

Dividends 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.

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. Temporary book-tax differences will reverse in a subsequent period.

Book-tax differences are primarily due to deferred trustees compensation.

The federal tax cost of investment securities and unrealized appreciation (depreciation) as of period end were as follows:

Gross unrealized appreciation	$ -
Gross unrealized depreciation	-
Net unrealized appreciation (depreciation) on securities and other investments	$ -
Tax Cost	$ 6,390,507

Annual Report

2. Significant Accounting Policies - continued

Income Tax Information and Distributions to Shareholders - continued

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

Undistributed ordinary income $ 45

The tax character of distributions paid was as follows:

	April 30, 2012	April 30, 2011
Ordinary Income	$ 601	$ 499

3. Fees and Other Transactions with Affiliates.

Management Fee. Fidelity Management & Research Company (FMR) 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. FMR pays all other expenses, except the compensation of the independent Trustees and certain exceptions such as interest expense. The management fee paid to FMR by the Fund is reduced by an amount equal to the fees and expenses paid by the Fund to the independent Trustees.

4. Expense Reductions.

FMR or its affiliates voluntarily agreed to waive certain fees in order to maintain a minimum annualized yield of .01%. Such arrangements may be discontinued by FMR at any time. For the period, the amount of the waiver was $22,063.

In addition, through arrangements with the Fund's custodian, credits realized as a result of uninvested cash balances were used to reduce the Fund's management fee. During the period, these credits reduced the Fund's management fee by $36.

5. Other.

The 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, the Fund may also enter into contracts that provide general indemnifications. The Fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against the Fund. The risk of material loss from such claims is considered remote.

Annual Report

Report of Independent Registered Public Accounting Firm

To the Trustees of Fidelity Hereford Street Trust and the Shareholders of Fidelity U.S. Treasury Money Market Fund:

In our opinion, the accompanying statement of assets and liabilities, including the schedule of investments, and the related statements of operations and of changes in net assets and the financial highlights present fairly, in all material respects, the financial position of Fidelity U.S. Treasury Money Market Fund (a fund of Fidelity Hereford Street Trust) at April 30, 2012, 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 five years in the period then ended, in conformity with accounting principles generally accepted in the United States of America. These financial statements and financial highlights (hereafter referred to as "financial statements") are the responsibility of the Fidelity U.S. Treasury Money Market Fund's management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits, which included confirmation of securities at April 30, 2012 by correspondence with the custodian and brokers, provide a reasonable basis for our opinion.

PricewaterhouseCoopers LLP

Boston, Massachusetts

June 6, 2012

Annual Report

Trustees and Officers

The Trustees and executive 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. Except for Mr. Curvey, each of the Trustees oversees 207 funds advised by FMR or an affiliate. Mr. Curvey oversees 435 funds advised by FMR or an affiliate.

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) (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. The executive officers hold office without limit in time, except that any officer 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.

Experience, Skills, Attributes, and Qualifications of the Fund's 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.

Annual Report

Board Structure and Oversight Function. Abigail P. Johnson is an interested person (as defined in the 1940 Act) 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. Kenneth L. Wolfe 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, and asset allocation funds and another Board oversees Fidelity's equity and high income funds. The asset allocation funds may invest in Fidelity funds that are overseen by such other Board. 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 FMR'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 Fund's Trustees."

Annual Report

Trustees and Officers - continued

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 each Trustee who is an interested person may be sent to Fidelity Investments, 82 Devonshire Street, Boston, Massachusetts 02109.

Name, Age; Principal Occupations and Other Relevant Experience+
Abigail P. Johnson (50)
	Year of Election or Appointment: 2009 Ms. Johnson is Trustee and Chairman of the Board of Trustees of certain Trusts. Ms. Johnson serves as President of Personal, Workplace and Institutional Services (2005-present). Ms. Johnson is Chairman and Director of FMR Co., Inc. (2011-present), Chairman and Director of FMR (2011-present), and the Vice Chairman and Director (2007-present) of FMR LLC. Previously, Ms. Johnson served as President and a Director of FMR (2001-2005), a Trustee of other investment companies advised by FMR, Fidelity Investments Money Management, Inc., 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.
James C. Curvey (76)
	Year of Election or Appointment: 2007 Mr. Curvey also serves as Trustee (2007-present) of other investment companies advised by FMR. Mr. Curvey is a Director of Fidelity Investments Money Management, Inc. (2009-present), Director of Fidelity Research & Analysis Co. (2009-present) and Director of FMR and FMR Co., Inc. (2007-present). Mr. Curvey is also Vice Chairman (2007-present) and Director of FMR LLC. In addition, Mr. Curvey serves as an Overseer for the Boston Symphony Orchestra and a member of the Trustees of Villanova University. Previously, Mr. Curvey was the Vice Chairman (2006-2007) and Director (2000-2007) of FMR Corp.

* Trustees have been determined to be "Interested Trustees" by virtue of, among other things, their affiliation with the trust or various entities under common control with FMR.

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

Independent Trustees:

Correspondence intended for each Independent Trustee (that is, the Trustees other than the Interested Trustees) may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Age; Principal Occupations and Other Relevant Experience+
Albert R. Gamper, Jr. (70)
	Year of Election or Appointment: 2006 Mr. Gamper is Vice Chairman of the Independent Trustees of the Fixed Income and Asset Allocation Funds (2011-present). Prior to his retirement in December 2004, Mr. Gamper served as Chairman of the Board of CIT Group Inc. (commercial finance). During his tenure with CIT Group Inc. Mr. Gamper served in numerous senior management positions, including Chairman (1987-1989; 1999-2001; 2002-2004), Chief Executive Officer (1987-2004), and President (2002-2003). Mr. Gamper currently serves as a member of the Board of Directors of Public Service Enterprise Group (utilities, 2000-present), a member of the Board of Trustees, Rutgers University (2004-present), and Chairman of the Board of Saint Barnabas Health Care System. Previously, Mr. Gamper served as Chairman of the Board of Governors, Rutgers University (2004-2007).
Robert F. Gartland (60)
	Year of Election or Appointment: 2010 Mr. Gartland is Chairman and an investor in Gartland and Mellina Group Corp. (consulting, 2009-present). Previously, Mr. Gartland served as a partner and investor of Vietnam Partners LLC (investments and consulting, 2008-2011). Prior to his retirement, Mr. Gartland held a variety of positions at Morgan Stanley (financial services, 1979-2007) including Managing Director (1987-2007).
Arthur E. Johnson (65)
	Year of Election or Appointment: 2008 Mr. Johnson serves as a member of the Board of Directors of Eaton Corporation (diversified power management, 2009-present), AGL Resources, Inc. (holding company, 2002-present) and Booz Allen Hamilton (management consulting, 2011-present). Prior to his retirement, Mr. Johnson served as Senior Vice President of Corporate Strategic Development of Lockheed Martin Corporation (defense contractor, 1999-2009). He previously served on the Board of Directors of IKON Office Solutions, Inc. (1999-2008) and Delta Airlines (2005-2007). Mr. Arthur E. Johnson is not related to Mr. Edward C. Johnson 3d or Ms. Abigail P. Johnson.
Michael E. Kenneally (58)
	Year of Election or Appointment: 2009 Previously, Mr. Kenneally served as a Member of the Advisory Board for certain Fidelity Fixed Income and Asset Allocation Funds (2008-2009). Prior to his retirement, Mr. Kenneally served as Chairman and Global Chief Executive Officer of Credit Suisse Asset Management (2003-2005). Mr. Kenneally was a Director of the Credit Suisse Funds (U.S. mutual funds, 2004-2008) and certain other closed-end funds (2004-2005) and was awarded the Chartered Financial Analyst (CFA) designation in 1991.
James H. Keyes (71)
	Year of Election or Appointment: 2007 Mr. Keyes serves as a member of the Boards of Navistar International Corporation (manufacture and sale of trucks, buses, and diesel engines, since 2002) and Pitney Bowes, Inc. (integrated mail, messaging, and document management solutions, since 1998). Prior to his retirement, Mr. Keyes served as Chairman and Chief Executive Officer of Johnson Controls (automotive, building, and energy, 1998-2002) and as a member of the Board of LSI Logic Corporation (semiconductor technologies, 1984-2008).
Marie L. Knowles (65)
	Year of Election or Appointment: 2001 Prior to Ms. Knowles' retirement in June 2000, she served as Executive Vice President and Chief Financial Officer of Atlantic Richfield Company (ARCO) (diversified energy, 1996-2000). From 1993 to 1996, she was a Senior Vice President of ARCO and President of ARCO Transportation Company. She served as a Director of ARCO from 1996 to 1998. Ms. Knowles currently serves as a Director and Chairman of the Audit Committee of McKesson Corporation (healthcare service, since 2002). Ms. Knowles is an Honorary Trustee of the Brookings Institution and a member of the Board of the Catalina Island Conservancy and of the Santa Catalina Island Company (2009-present). She also serves as a member of the Advisory Board for the School of Engineering of the University of Southern California and the Foundation Board of the School of Architecture at the University of Virginia (2007-present). Previously, Ms. Knowles served as a Director of Phelps Dodge Corporation (copper mining and manufacturing, 1994-2007).
Kenneth L. Wolfe (73)
	Year of Election or Appointment: 2005 Mr. Wolfe is Chairman of the Independent Trustees of the Fixed Income and Asset Allocation Funds (2008-present). Prior to his retirement, Mr. Wolfe served as Chairman and a Director (2007-2009) and Chairman and Chief Executive Officer (1994-2001) of Hershey Foods Corporation. He also served as a member of the Boards of Adelphia Communications Corporation (telecommunications, 2003-2006), Bausch & Lomb, Inc. (medical/pharmaceutical, 1993-2007), and Revlon, Inc. (personal care products, 2004-2009).

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

Annual Report

Trustees and Officers - continued

Executive Officers:

Correspondence intended for each executive officer may be sent to Fidelity Investments, 82 Devonshire Street, Boston, Massachusetts 02109.

Name, Age; Principal Occupation
John R. Hebble (53)
	Year of Election or Appointment: 2008 President and Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Hebble also serves as President (2011-present), Treasurer, and Chief Financial Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present), Assistant Treasurer of other Fidelity funds (2009-present) and is an employee of Fidelity Investments.
Robert P. Brown (48)
	Year of Election or Appointment: 2010 Vice President of Fidelity's Money Market Funds and Executive Vice President of Fidelity Investments Money Management, Inc. (2010-present). Mr. Brown also serves as President, Money Market Group of FMR (2010-present), Managing Director of Research, Director of Fidelity Management & Research (U.K.) Inc. (2008-present) and is an employee of Fidelity Investments.
Scott C. Goebel (44)
	Year of Election or Appointment: 2008 Secretary and Chief Legal Officer (CLO) of the Fidelity funds. Mr. Goebel also serves as Secretary of Fidelity Investments Money Management, Inc. (FIMM) (2010-present) and Fidelity Research and Analysis Company (FRAC) (2010-present); Secretary and CLO of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present); General Counsel, Secretary, and Senior Vice President of FMR (2008-present) and FMR Co., Inc. (2008-present); employed by FMR LLC or an affiliate (2001-present); Chief Legal Officer of Fidelity Management & Research (Hong Kong) Limited (2008-present) and Assistant Secretary of Fidelity Management & Research (Japan) Inc. (2008-present), and Fidelity Management & Research (U.K.) Inc. (2008-present). Previously, Mr. Goebel served as Assistant Secretary of FIMM (2008-2010), FRAC (2008-2010), and the Funds (2007-2008) and as Vice President and Secretary of Fidelity Distributors Corporation (FDC) (2005-2007).
David J. Carter (38)
	Year of Election or Appointment: 2010 Assistant Secretary of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Carter also serves as Vice President, Associate General Counsel (2010-present) and is an employee of Fidelity Investments (2005-present).
Elizabeth Paige Baumann (43)
	Year of Election or Appointment: 2012 Anti-Money Laundering (AML) Officer of the Fidelity funds. Ms. Baumann also serves as AML Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2012-present), Chief AML Officer of FMR LLC (2012-present), and is an employee of Fidelity Investments. Previously, Ms. Baumann served as Vice President and Deputy Anti-Money Laundering Officer (2007-2012).
Christine Reynolds (53)
	Year of Election or Appointment: 2008 Chief Financial Officer of the Fidelity funds. Ms. Reynolds became President of Fidelity Pricing and Cash Management Services (FPCMS) in August 2008. Ms. Reynolds served as Chief Operating Officer of FPCMS (2007-2008). Previously, Ms. Reynolds served as President, Treasurer, and Anti-Money Laundering officer of the Fidelity funds (2004-2007).
Michael H. Whitaker (44)
	Year of Election or Appointment: 2008 Chief Compliance Officer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Whitaker also serves as Chief Compliance Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present). Mr. Whitaker is an employee of Fidelity Investments (2007-present). Prior to joining Fidelity Investments, Mr. Whitaker worked at MFS Investment Management where he served as Senior Vice President and Chief Compliance Officer (2004-2006), and Assistant General Counsel.
Joseph F. Zambello (54)
	Year of Election or Appointment: 2011 Deputy Treasurer of the Fidelity funds. Mr. Zambello is an employee of Fidelity Investments. Previously, Mr. Zambello served as Vice President of FMR's Program Management Group (2009-2011) and Vice President of the Transfer Agent Oversight Group (2005-2009).
Stephanie J. Dorsey (42)
	Year of Election or Appointment: 2008 Deputy Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Ms. Dorsey also serves as Assistant Treasurer of other Fidelity funds (2010-present) and is an employee of Fidelity Investments (2008-present). Previously, Ms. Dorsey served as Treasurer (2004-2008) of the JPMorgan Mutual Funds and Vice President (2004-2008) of JPMorgan Chase Bank.
Adrien E. Deberghes (44)
	Year of Election or Appointment: 2010 Assistant Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Deberghes also serves as Vice President and Assistant Treasurer (2011-present) and Deputy Treasurer (2008-present) of other Fidelity funds, and is an employee of Fidelity Investments (2008-present). Previously, Mr. Deberghes served as Senior Vice President of Mutual Fund Administration at State Street Corporation (2007-2008), Senior Director of Mutual Fund Administration at Investors Bank & Trust (2005-2007), and Director of Finance for Dunkin' Brands (2000-2005).
Kenneth B. Robins (42)
	Year of Election or Appointment: 2009 Assistant Treasurer of the Fidelity Fixed Income and Asset Allocation Funds. Mr. Robins also serves as President and Treasurer of other Fidelity funds (2008-present; 2010-present) and is an employee of Fidelity Investments (2004-present). Previously, Mr. Robins served as Deputy Treasurer of the Fidelity funds (2005-2008) and Treasurer and Chief Financial Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2006-2008).
Gary W. Ryan (53)
	Year of Election or Appointment: 2005 Assistant Treasurer of the Fidelity funds. Mr. Ryan is an employee of Fidelity Investments. Previously, Mr. Ryan served as Vice President of Fund Reporting in Fidelity Pricing and Cash Management Services (FPCMS) (1999-2005).
Jonathan Davis (43)
	Year of Election or Appointment: 2010 Assistant Treasurer of the Fidelity funds. Mr. Davis is also Assistant Treasurer of Fidelity Rutland Square Trust II and Fidelity Commonwealth Trust II. Mr. Davis is an employee of Fidelity Investments. Previously, Mr. Davis served as Vice President and Associate General Counsel of FMR LLC (2003-2010).

Annual Report

Distributions (Unaudited)

The fund hereby designates as a capital gain dividend with respect to the taxable year ended April 30, 2012, $116, or, if subsequently determined to be different, the net capital gain of such year.

A total of 100% 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 $208,868 of distributions paid during the period January 1, 2012 to April 30, 2012 as qualifying to be taxed as interest-related dividends for nonresident alien shareholders.

The fund will notify shareholders in January 2013 of amounts for use in preparing 2012 income tax returns.

Annual Report

Investment Adviser

Fidelity Management & Research
Company
Boston, MA

Investment Sub-Advisers

Fidelity Investments
Money Management, Inc.

Fidelity Management & Research
(U.K.) Inc.

Fidelity Management & Research
(Hong Kong) Limited

Fidelity Management & Research
(Japan) Inc.

General Distributor

Fidelity Distributors Corporation

Boston, MA

Transfer and Service Agents

Fidelity Investments Institutional
Operations Company, Inc.

Boston, MA

Fidelity Service Company, Inc.

Boston, MA

Custodian

JPMorgan Chase Bank

New York, NY

The Fidelity Telephone Connection

Mutual Fund 24-Hour Service

Exchanges/Redemptions
and Account Assistance 1-800-544-6666

Product Information 1-800-544-6666

Retirement Accounts 1-800-544-4774 (8 a.m. - 9 p.m.)

TDD Service 1-800-544-0118
for the deaf and hearing impaired
(9 a.m. - 9 p.m. Eastern time)

Fidelity Automated Service
Telephone (FAST®)
1-800-544-5555

Automated line for quickest service

(Fidelity Investment logo)(registered trademark)
Corporate Headquarters
82 Devonshire St., Boston, MA 02109
www.fidelity.com

TMM-UANN-0612
1.784734.109

Fidelity®

Money Market

Fund

Annual Report

April 30, 2012

(Fidelity Cover Art)

Contents

Shareholder Expense Example	(Click Here)	An example of shareholder expenses.
Investment Changes/Performance	(Click Here)	A summary of major shifts in the fund's investments over the past six months.
Investments	(Click Here)	A complete list of the fund's investments.
Financial Statements	(Click Here)	Statements of assets and liabilities, operations, and changes in net assets, as well as financial highlights.
Notes	(Click Here)	Notes to the financial statements.
Report of Independent Registered Public Accounting Firm	(Click Here)
Trustees and Officers	(Click Here)
Distributions	(Click Here)

To view a fund's proxy voting guidelines and proxy voting record for the 12-month period ended June 30, visit http://www.fidelity.com/proxyvotingresults or visit the Securities and Exchange Commission's (SEC) web site at http://www.sec.gov. 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.

All other marks appearing herein are registered or unregistered trademarks or service marks of FMR LLC or an affiliated company.

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-Q. Forms N-Q are available on the SEC's web site at http://www.sec.gov. A fund's Forms N-Q 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.advisor.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.

Annual Report

Shareholder Expense Example

As a shareholder of the Fund, you incur two types of costs: (1) transaction costs, and (2) ongoing costs, including management fees and other Fund expenses. This Example is intended to help you understand your ongoing costs (in dollars) of investing in the 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, 2011 to April 30, 2012).

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 under the heading entitled "Expenses Paid During Period" to estimate the expenses you paid on your account during this period. A small balance maintenance fee of $12.00 that is charged once a year may apply for certain accounts with a value of less than $2,000. This fee is not included in the table below. If it was, the estimate of expenses you paid during the period would be higher, and your ending account value lower, by this amount.

Hypothetical Example for Comparison Purposes

The second line of the accompanying table provides information about hypothetical account values and hypothetical expenses based on the Fund's actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Fund's 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. A small balance maintenance fee of $12.00 that is charged once a year may apply for certain accounts with a value of less than $2,000. This fee is not included in the table below. If it was, the estimate of expenses you paid during the period would be higher, and your ending account value lower, by this amount.

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.

Annual Report

Shareholder Expense Example - continued

	Annualized Expense Ratio	Beginning Account Value November 1, 2011	Ending Account Value April 30, 2012	Expenses Paid During Period* November 1, 2011 to April 30, 2012
Actual	.42%	$ 1,000.00	$ 1,000.05	$ 2.09
Hypothetical (5% return per year before expenses)		$ 1,000.00	$ 1,022.77	$ 2.11

* Expenses are equal to the Fund's annualized expense ratio, multiplied by the average account value over the period, multiplied by 182/366 (to reflect the one-half year period).

Annual Report

Investment Changes/Performance (Unaudited)

Effective Maturity Diversification
Days	% of fund's investments 4/30/12	% of fund's investments 10/31/11	% of fund's investments 4/30/11
1 - 7	23.3	27.6	26.6
8 - 30	33.0	25.1	26.2
31 - 60	12.9	13.7	12.0
61 - 90	12.1	16.2	17.7
91 - 180	11.5	10.3	12.4
> 180	7.2	7.1	5.1

Effective maturity is determined in accordance with the requirements of Rule 2a-7 under the Investment Company Act of 1940.

Weighted Average Maturity
	4/30/12	10/31/11	4/30/11
Fidelity Money Market Fund	52 Days	55 Days	52 Days
All Taxable Money Market Funds Average*	45 Days	42 Days	45 Days

This is a weighted average of all the maturities of the securities held in a fund. Weighted Average Maturity (WAM) can be used as a measure of sensitivity to interest rate changes and market changes. Generally, the longer the maturity, the greater the sensitivity to such changes. WAM is based on the dollar-weighted average length of time until principal payments must be paid. Depending on the types of securities held in a fund, certain maturity shortening devices (e.g., demand features, interest rate resets, and call options) may be taken into account when calculating the WAM.

Weighted Average Life
	4/30/12	10/31/11	4/30/11
Fidelity Money Market Fund	92 Days	100 Days	98 Days

Weighted Average Life (WAL) is the weighted average of the life of the securities held in a fund or portfolio and can be used as a measure of sensitivity to changes in liquidity and/or credit risk. Generally, the higher the value, the greater the sensitivity. WAL is based on the dollar-weighted average length of time until 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. The difference between WAM and WAL is that WAM takes into account interest rate resets and WAL does not. WAL for money market funds is not the same as WAL of a mortgage- or asset-backed security.

Asset Allocation (% of fund's net assets)
As of April 30, 2012		As of October 31, 2011
	Certificates of Deposit 39.9%		Certificates of Deposit 48.3%
	Commercial Paper 25.1%		Commercial Paper 14.7%
	Variable Rate Demand Notes (VRDNs) 3.8%		Variable Rate Demand Notes (VRDNs) 3.5%
	Other Note 7.3%		Other Note 8.1%
	Treasury Debt 11.2%		Treasury Debt 6.6%
	Government Agency Debt 0.9%		Government Agency Debt† 4.0%
	Insurance Company Funding Agreements 0.7%		Insurance Company Funding Agreements 0.7%
	Other Municipal Debt 0.4%		Other Municipal Debt 0.4%
	Other Instruments 0.0%		Other Instruments 0.7%
	Repurchase Agreements 10.8%		Repurchase Agreements 14.9%
	Net Other Assets (Liabilities) ** (0.1)%		Net Other Assets (Liabilities) ** (1.9)%

Current and Historical Seven-Day Yields

	4/30/12	1/31/12	11/1/11	8/2/11	5/3/11
Fidelity Money Market Fund	0.01%	0.01%	0.01%	0.01%	0.01%

Yield refers to the income paid by the fund over a given period. Yields for money market funds are usually for seven-day periods, as they are here, though they are expressed as annual percentage rates. 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, 2012, the most recent period shown in the table, would have been 0.00%.

* Source: iMoneyNet, Inc.

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

^† Includes Federal Financing Bank Supported Student Loan Short-Term Notes.

Annual Report

Investments April 30, 2012

Showing Percentage of Net Assets

Certificate of Deposit - 39.9%
		Yield (a)	Principal Amount (000s)	Value (000s)
Domestic Certificates Of Deposit - 0.7%
Branch Banking & Trust Co.
	5/3/12 to 11/1/12	0.35 to 0.42%	$ 24,000	$ 24,000
London Branch, Eurodollar, Foreign Banks - 7.0%
ABN AMRO Bank NV
	5/18/12	0.30	14,000	14,000
Australia & New Zealand Banking Group Ltd.
	6/6/12	0.61	7,000	7,000
Commonwealth Bank of Australia
	8/8/12	0.40	16,000	16,000
HSBC Bank PLC
	5/3/12 to 5/31/12	0.50 to 0.51	21,000	21,000
ING Bank NV
	5/14/12 to 6/1/12	0.37 to 0.40	71,000	71,000
Mitsubishi UFJ Trust & Banking Corp.
	5/3/12	0.51	6,000	6,000
National Australia Bank Ltd.
	5/2/12 to 10/11/12	0.35 to 0.52 (d)	101,000	101,000
				236,000
New York Branch, Yankee Dollar, Foreign Banks - 32.2%
Bank of Montreal Chicago CD Program
	9/26/12 to 5/6/13	0.39 to 0.56 (d)	61,000	61,000
Bank of Nova Scotia
	7/5/12 to 5/10/13	0.31 to 0.77 (d)	129,600	129,620
Bank of Tokyo-Mitsubishi UFJ Ltd.
	8/10/12 to 9/21/12	0.42 to 0.50 (d)	71,000	71,000
Canadian Imperial Bank of Commerce
	10/1/12	0.50	37,000	37,000
	9/24/12 to 5/17/13	0.41 to 0.67 (d)	89,000	89,005
Mitsubishi UFJ Trust & Banking Corp.
	5/10/12 to 7/27/12	0.41 to 0.50	54,000	54,000
Mizuho Corporate Bank Ltd.
	5/14/12 to 7/3/12	0.40	83,000	83,000
National Bank Canada
	7/6/12 to 2/4/13	0.35 to 0.64 (d)	37,000	37,000
Nordea Bank Finland PLC
	6/15/12	0.36	2,000	2,000
Certificate of Deposit - continued
		Yield (a)	Principal Amount (000s)	Value (000s)
New York Branch, Yankee Dollar, Foreign Banks - continued
Rabobank Nederland New York Branch
	6/1/12 to 6/14/12	0.29 to 0.50% (d)	$ 88,000	$ 88,000
Royal Bank of Canada
	5/1/13	0.83 (d)	56,000	56,000
Royal Bank of Scotland PLC Connecticut Branch
	6/27/12	0.40	32,000	32,000
Societe Generale
	5/2/12	0.35	12,000	12,000
Sumitomo Mitsui Banking Corp.
	5/8/12 to 7/3/12	0.38 to 0.40 (d)	123,000	123,000
Sumitomo Trust & Banking Co. Ltd.
	5/8/12 to 8/3/12	0.45 to 0.50	60,000	60,000
Toronto-Dominion Bank
	11/7/12 to 2/4/13	0.44 to 0.54 (d)	32,000	32,000
	7/30/12 to 11/14/12	0.28 to 0.62	59,000	59,000
UBS AG
	6/22/12	0.35	65,000	65,000
				1,090,625
TOTAL CERTIFICATE OF DEPOSIT				1,350,625
Financial Company Commercial Paper - 17.8%
ASB Finance Ltd. (London)
	5/22/12	0.68	38,000	37,985
Barclays Bank PLC
	5/2/12 to 5/22/12	0.74 to 0.78 (b)	27,000	27,000
Barclays Bank PLC/Barclays U.S. CCP Funding LLC
	5/2/12 to 5/21/12	0.37 to 0.38	7,000	6,999
BAT International Finance PLC
	5/4/12 to 5/9/12	0.43	4,000	4,000
BNP Paribas Finance, Inc.
	5/2/12 to 6/4/12	0.37	70,000	69,987
BP Capital Markets PLC
	6/8/12	0.25	6,000	5,998
Financial Company Commercial Paper - continued
		Yield (a)	Principal Amount (000s)	Value (000s)
Caisse d'Amort de la Dette Sociale
	5/25/12	0.54% (b)(d)	$ 14,000	$ 14,000
Citigroup Funding, Inc.
	5/10/12 to 6/8/12	0.50	72,000	71,980
Commonwealth Bank of Australia
	5/3/12 to 6/15/12	0.50 to 0.62	34,000	33,988
Credit Suisse New York Branch
	6/11/12	0.30	35,000	34,988
Danske Corp.
	5/9/12 to 5/11/12	0.30	76,000	75,994
DNB Bank ASA
	6/11/12 to 6/29/12	0.30 to 0.40	18,000	17,992
JPMorgan Chase & Co.
	8/1/12 to 9/12/12	0.29 to 0.30 (d)	60,000	59,971
Mitsubishi UFJ Trust & Banking Corp.
	5/2/12 to 5/3/12	0.40 to 0.46	9,000	9,000
Rabobank USA Financial Corp.
	6/6/12	0.37	6,000	5,998
Skandinaviska Enskilda Banken AB
	5/7/12 to 5/16/12	0.40	35,000	34,997
Societe Generale North America, Inc.
	5/2/12	0.35	12,000	12,000
Svenska Handelsbanken, Inc.
	6/15/12	0.32	2,000	1,999
Swedbank AB
	5/1/12 to 5/22/12	0.43 to 0.55	26,000	25,996
UBS Finance, Inc.
	5/4/12 to 6/4/12	0.36 to 0.50	54,000	53,987
TOTAL FINANCIAL COMPANY COMMERCIAL PAPER				604,859
Asset Backed Commercial Paper - 6.2%
Amsterdam Funding Corp. (Royal Bank of Scotland PLC Guaranteed)
	5/17/12	0.33 (b)	6,000	5,999
Autobahn Funding Co. LLC (Liquidity Facility DZ BANK AG)
	5/11/12	0.48	8,000	7,999
Asset Backed Commercial Paper - continued
		Yield (a)	Principal Amount (000s)	Value (000s)
Ciesco LP (Citibank NA Guaranteed)
	5/11/12 to 5/29/12	0.34 to 0.35%	$ 19,000	$ 18,996
Citigroup Funding, Inc.
	5/25/12	0.50	24,000	23,992
Comcast Corp.
	5/31/12	0.45	1,000	1,000
Commonwealth Bank of Australia
	10/22/12	0.29 (d)	5,000	5,000
Danske Corp.
	5/1/12 to 5/8/12	0.30	93,000	92,998
Govco, Inc. (Liquidity Facility Citibank NA)
	5/7/12 to 6/4/12	0.34 to 0.37	45,000	44,991
Viacom, Inc.
	5/7/12 to 5/16/12	0.42	4,000	4,000
Windmill Funding Corp. (Royal Bank of Scotland PLC Guaranteed)
	5/16/12	0.33 (b)	4,000	3,999
TOTAL ASSET BACKED COMMERCIAL PAPER				208,974
Other Commercial Paper - 1.1%
Comcast Corp.
	6/8/12	0.45	1,000	1,000
Devon Energy Corp.
	5/30/12	0.44 (d)	17,000	17,000
Ecolab, Inc.
	5/30/12	0.52 (d)	12,000	12,000
Sempra Global
	5/7/12 to 5/29/12	0.40 to 0.42	3,000	2,999
Texas Instruments International Management Co. S.a.r.L.
	7/9/12	0.43	1,000	999
Verizon Communications, Inc.
	5/14/12 to 5/15/12	0.40	2,000	2,000
Viacom, Inc.
	5/10/12 to 5/21/12	0.40 to 0.42	3,000	3,000
TOTAL OTHER COMMERCIAL PAPER				38,998
Treasury Debt - 11.2%
		Yield (a)	Principal Amount (000s)	Value (000s)
U.S. Treasury Obligations - 11.2%
U.S. Treasury Bills
	8/9/12 to 4/4/13	0.10 to 0.18% (c)	$ 91,500	$ 91,424
U.S. Treasury Notes
	6/30/12 to 4/15/13	0.11 to 0.23	284,930	286,873
TOTAL TREASURY DEBT				378,297
Other Note - 7.3%
Medium-Term Notes - 7.3%
Royal Bank of Canada
	5/1/13 to 5/15/13	0.52 to 0.86 (b)(d)	114,300	114,300
Westpac Banking Corp.
	5/23/12 to 6/14/12	0.38 to 0.62 (b)(d)	133,000	133,000
TOTAL OTHER NOTE				247,300
Variable Rate Demand Note - 3.8%
Arizona - 0.2%
Arizona Health Facilities Auth. Rev. (Catholic Healthcare West Proj.) Series 2005 B, LOC JPMorgan Chase Bank, VRDN
	5/7/12	0.24 (d)	5,430	5,430
California - 0.8%
California Statewide Cmntys. Dev. Auth. Multi-family Hsg. Rev. (The Belmont Proj.) Series 2005 F, LOC Fannie Mae, VRDN
	5/7/12	0.22 (d)(e)	10,500	10,500
Contra Costa County Multi-family Hsg. Rev. (Avalon Walnut Creek Contra Costa Centre Proj.) Series 2008 A, LOC Bank of America NA, VRDN
	5/7/12	0.25 (d)(e)	10,000	10,000
Newport Beach Rev. (Hoag Memorial Hosp. Presbyterian Proj.) Series 2008 F, LOC Bank of America NA, VRDN
	5/7/12	0.29 (d)	7,905	7,905
				28,405
Variable Rate Demand Note - continued
		Yield (a)	Principal Amount (000s)	Value (000s)
Colorado - 0.3%
Denver City & County Arpt. Rev. Series 2009 C, LOC JPMorgan Chase Bank, VRDN
	5/7/12	0.23% (d)	$ 9,900	$ 9,900
Florida - 0.6%
Broward County Port Facilities Rev. (Port Everglades Proj.) Series 2008, LOC Bank of Nova Scotia New York Branch, VRDN
	5/7/12	0.23 (d)(e)	9,165	9,165
Pinellas County Health Facilities Auth. Rev. (BayCare Health Sys. Proj.) Series 2009 A3, LOC Wells Fargo Bank NA, VRDN
	5/7/12	0.24 (d)	10,275	10,275
				19,440
Maryland - 0.4%
Maryland Cmnty. Dev. Administration Dept. of Hsg. & Cmnty. Dev. (Barrington Apts. Proj.) Series A, LOC Fannie Mae, VRDN
	5/7/12	0.24 (d)(e)	12,190	12,190
New York - 0.5%
New York City Health & Hosp. Corp. Rev. Series 2008 C, LOC TD Banknorth, NA, VRDN
	5/7/12	0.20 (d)	6,100	6,100
New York Hsg. Fin. Agcy. Rev. (Shore Hill Hsg. Proj.) Series 2008 A, LOC Freddie Mac, VRDN
	5/7/12	0.23 (d)	10,200	10,200
				16,300
Non State Specific - 0.4%
LP Pinewood SPV LLC Taxable, LOC Wells Fargo Bank NA, VRDN
	5/7/12	0.21 (d)	11,700	11,700
Pennsylvania - 0.3%
Philadelphia Wtr. & Wastewtr. Rev. Series 2005 B, LOC Bank of America NA, VRDN
	5/7/12	0.25 (d)	10,500	10,500
South Carolina - 0.3%
South Carolina Jobs-Econ. Dev. Auth. Econ. Dev. Rev. (Bon Secours Health Sys. Proj.) Series 2008 D, LOC Citibank NA, VRDN
	5/7/12	0.24 (d)	12,100	12,100
TOTAL VARIABLE RATE DEMAND NOTE				125,965
Government Agency Debt - 0.9%
		Yield (a)	Principal Amount (000s)	Value (000s)
Federal Agencies - 0.9%
Federal Home Loan Bank
	5/16/12 to 11/28/12	0.16 to 0.41%	$ 31,667	$ 31,665
Insurance Company Funding Agreement - 0.7%
Medium-Term Notes - 0.7%
Metropolitan Life Insurance Co.
	7/20/12	0.80 (d)(f)	25,000	25,000
Other Instrument - 0.0%
Asset-Backed Securities - 0.0%
Huntington Auto Trust 2011-1
	9/17/12	0.36 (b)	398	398

Other Municipal Debt - 0.4%

New Hampshire - 0.4%
New Hampshire Bus. Fin. Auth. Poll. Cont. Rev. Bonds (New England Pwr. Co. Proj.) Series 1990 A, 0.4% tender 5/7/12, CP mode (e)	14,000		14,000
Government Agency Repurchase Agreement - 0.3%
	Maturity Amount (000s)
In a joint trading account at 0.23% dated 4/30/12 due 5/1/12 (Collateralized by (U.S. Government Obligations)) #	$ 278		278
With Barclays Capital, Inc. at 0.2%, dated 3/22/12 due 5/7/12 (Collateralized by U.S. Treasury Obligations valued at $11,222,494, 0.2%, 11/1/26 - 3/1/42)	11,006		11,000
TOTAL GOVERNMENT AGENCY REPURCHASE AGREEMENT		11,278
Other Repurchase Agreement - 10.5%
	Maturity Amount (000s)		Value (000s)
Other Repurchase Agreement - 10.5%
With:
Barclays Capital, Inc. at:
0.35%, dated 4/24/12 due 5/1/12 (Collateralized by Equity Securities valued at $4,319,230)	$ 4,000		$ 4,000
0.61%, dated 4/30/12 due 5/1/12 (Collateralized by Corporate Obligations valued at $76,363,640, 1.75% - 7%, 5/15/14 - 3/15/37)	71,001		71,000
Credit Suisse Securities (USA) LLC at:
0.9%, dated 4/18/12 due 7/18/12 (Collateralized by Equity Securities valued at $25,922,109)	24,001		24,000
0.87%, dated 4/12/12 due 7/11/12 (Collateralized by Mortgage Loan Obligations valued at $12,965,834, 0.53% - 5.96%, 7/25/34 - 9/12/49)	12,026		12,000
0.9%, dated:
4/3/12 due 7/3/12 (Collateralized by Corporate Obligations valued at $3,246,113, 3.86% - 5.44%, 1/25/36 - 5/20/41)	3,007		3,000
4/18/12 due 7/18/12 (Collateralized by Mortgage Loan Obligations valued at $9,723,018, 0.53% - 5.87%, 11/25/35 - 9/12/49)	9,020		9,000
4/24/12 due 7/23/12 (Collateralized by Corporate Obligations valued at $6,483,968, 0.42% - 0.63%, 1/25/36 - 6/25/37)	6,014		6,000
0.94%, dated:
2/17/12 due 5/17/12 (Collateralized by Corporate Obligations valued at $6,494,384, 0.63% - 0.69%, 6/25/35 - 1/25/36)	6,014		6,000
2/21/12 due 5/22/12 (Collateralized by Corporate Obligations valued at $6,494,541, 0.42%, 6/25/37)	6,014		6,000
2/24/12 due 5/25/12 (Collateralized by Corporate Obligations valued at $3,249,576, 3.86% - 5.44%, 1/25/36 - 5/20/41)	3,007		3,000
0.95%, dated 2/10/12 due 5/10/12 (Collateralized by Corporate Obligations valued at $3,250,875, 3.86% - 5.44%, 1/25/36 - 5/20/41)	3,007		3,000
0.97%, dated:
2/1/12 due 5/1/12 (Collateralized by Corporate Obligations valued at $13,676,145, 7.25%, 5/15/14)	13,032		13,000
2/3/12 due 5/3/12 (Collateralized by Corporate Obligations valued at $2,165,385, 0.53% - 5.87%, 11/25/35 - 9/15/45)	2,005		2,000
Other Repurchase Agreement - continued
	Maturity Amount (000s)		Value (000s)
Other Repurchase Agreement - continued
With: - continued
ING Financial Markets LLC at 0.34%, dated:
4/16/12 due 5/7/12 (Collateralized by Corporate Obligations valued at $2,102,378, 5.6% - 6.9%, 11/30/17 - 5/29/67)	$ 2,001		$ 2,000
4/23/12 due 5/7/12 (Collateralized by Corporate Obligations valued at $1,050,083, 6.05% - 6.9%, 5/16/16 - 5/29/67)	1,000		1,000
J.P. Morgan Clearing Corp. at:
0.64%, dated 4/23/12 due 7/20/12 (Collateralized by Equity Securities valued at $4,000,572)	4,006		4,000
0.87%, dated 4/23/12 due 10/19/12 (Collateralized by Equity Securities valued at $8,697,364)	8,035		8,000
1.05%, dated 1/23/12 due 7/23/12 (Collateralized by Corporate Obligations valued at $18,532,048, 1.88% - 2.5%, 4/23/17 - 5/15/37)	17,090		17,000
J.P. Morgan Securities, Inc. at:
0.33%, dated 4/30/12 due 5/1/12 (Collateralized by Corporate Obligations valued at $58,804,648, 1.1% - 7.55%, 4/7/14 - 1/14/42)	56,001		56,000
0.49%, dated 4/19/12 due 5/7/12 (Collateralized by Mortgage Loan Obligations valued at $8,641,340, 6%, 6/25/37)	8,003		8,000
0.95%, dated 3/26/12 due 9/21/12 (Collateralized by Mortgage Loan Obligations valued at $6,487,792, 6%, 6/25/37)	6,028		6,000
Mizuho Securities USA, Inc. at 0.43%, dated 4/23/12 due 5/7/12 (Collateralized by Corporate Obligations valued at $6,300,744, 3.75% - 5.25%, 10/15/12 - 7/15/27)	6,002		6,000
RBS Securities, Inc. at:
0.6%, dated 4/25/12 due 5/2/12 (Collateralized by U.S. Government Obligations valued at $33,995,092, 3.71% - 5.03%, 5/16/30 - 12/16/50)	33,004		33,000
0.67%, dated 4/12/12 due 5/7/12 (Collateralized by U.S. Government Obligations valued at $8,245,320, 4.5%, 5/15/40)	8,004		8,000
0.85%, dated 4/18/12 due 5/18/12 (Collateralized by U.S. Government Obligations valued at $16,485,704, 3.5% - 5.5%, 1/15/39 - 2/15/42)	16,011		16,000
Royal Bank of Scotland PLC at:
0.6%, dated 4/25/12 due 5/2/12 (Collateralized by Corporate Obligations valued at $12,602,400, 1.11%, 8/15/22)	12,001		12,000
0.67%, dated 4/12/12 due 5/7/12 (Collateralized by Corporate Obligations valued at $6,305,650, 1.11%, 8/15/22)	6,003		6,000
Other Repurchase Agreement - continued
	Maturity Amount (000s)		Value (000s)
Other Repurchase Agreement - continued
With: - continued
UBS Securities LLC at:
0.47%, dated 4/9/12 due 5/7/12 (Collateralized by Corporate Obligations valued at $4,321,363, 2.25% - 4.75%, 6/15/13 - 12/15/66)	$ 4,003		$ 4,000
0.5%, dated 4/23/12 due 5/7/12 (Collateralized by Corporate Obligations valued at $3,240,360, 11% - 11.88%, 5/1/15 - 8/1/16)	3,003		3,000
0.59%, dated 2/21/12 due 5/7/12 (Collateralized by Corporate Obligations valued at $3,153,615, 9.25%, 8/6/19)	3,004		3,000
TOTAL OTHER REPURCHASE AGREEMENT		355,000
TOTAL INVESTMENT PORTFOLIO - 100.1% (Cost $3,392,359)			3,392,359
NET OTHER ASSETS (LIABILITIES) - (0.1)%			(4,809)
NET ASSETS - 100%		$ 3,387,550

Security Type Abbreviations
CP	-	COMMERCIAL PAPER
VRDN	-	VARIABLE RATE DEMAND NOTE (A debt instrument that is payable upon demand, either daily, weekly or monthly)

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) 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 $298,696,000 or 8.8% of net assets.

(c) Security or a portion of the security was pledged to cover open reverse repurchase agreements. At the period end, the value of securities pledged amounted to $1,999,000. The principal amount of the outstanding reverse repurchase agreement is $1,999,000.

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

(e) Private activity obligations whose interest is subject to the federal alternative minimum tax for individuals.

(f) Restricted securities - Investment in securities not registered under the Securities Act of 1933 (excluding 144A issues). At the end of the period, the value of restricted securities (excluding 144A issues) amounted to $25,000,000 or 0.7% of net assets.

Additional information on each restricted holding is as follows:

Security	Acquisition Date	Cost (000s)
Metropolitan Life Insurance Co. 0.8%, 7/20/12	3/26/02	$ 25,000

# Additional information on each counterparty to the repurchase agreement is as follows:

Repurchase Agreement / Counterparty	Value (Amounts in thousands)
$278,000 due 5/01/12 at 0.23%
Credit Agricole CIB New York Branch	$ 54
Mizuho Securities USA, Inc.	224
	$ 278

Other Information

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.

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 those securities. For more information on valuation inputs, please refer to the Security Valuation section in the accompanying Notes to Financial Statements.

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Statements

Statement of Assets and Liabilities

Amounts in thousands (except per-share amount)	April 30, 2012
Assets
Investment in securities, at value (including repurchase agreements of $366,278) - See accompanying schedule: Unaffiliated issuers (cost $3,392,359)		$ 3,392,359
Cash		57
Receivable for fund shares sold		5,165
Interest receivable		2,361
Other receivables		148
Total assets		3,400,090
Liabilities
Payable for fund shares redeemed	$ 9,187
Distributions payable	1
Accrued management fee	1,195
Payable for reverse repurchase agreement	1,999
Other affiliated payables	7
Other payables and accrued expenses	151
Total liabilities		12,540
Net Assets		$ 3,387,550
Net Assets consist of:
Paid in capital		$ 3,387,738
Distributions in excess of net investment income		(117)
Accumulated undistributed net realized gain (loss) on investments		(71)
Net Assets, for 3,386,734 shares outstanding		$ 3,387,550
Net Asset Value, offering price and redemption price per share ($3,387,550 ÷ 3,386,734 shares)		$ 1.00

See accompanying notes which are an integral part of the financial statements.

Annual Report

Statement of Operations

Amounts in thousands	Year ended April 30, 2012
Investment Income
Interest		$ 14,717
Expenses
Management fee	$ 16,046
Independent trustees' compensation	15
Total expenses before reductions	16,061
Expense reductions	(1,732)	14,329
Net investment income (loss)		388
Realized and Unrealized Gain (Loss) Net realized gain (loss) on:
Investment securities:
Unaffiliated issuers		40
Net increase in net assets resulting from operations		$ 428

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Statements - continued

Statement of Changes in Net Assets

Amounts in thousands	Year ended April 30, 2012	Year ended April 30, 2011
Increase (Decrease) in Net Assets
Operations
Net investment income (loss)	$ 388	$ 1,443
Net realized gain (loss)	40	(111)
Net increase in net assets resulting from operations	428	1,332
Distributions to shareholders from net investment income	(389)	(1,442)
Distributions to shareholders from net realized gain	-	(243)
Total distributions	(389)	(1,685)
Share transactions at net asset value of $1.00 per share Proceeds from sales of shares	1,489,461	2,279,633
Reinvestment of distributions	369	1,599
Cost of shares redeemed	(2,299,051)	(4,540,791)
Net increase (decrease) in net assets and shares resulting from share transactions	(809,221)	(2,259,559)
Total increase (decrease) in net assets	(809,182)	(2,259,912)
Net Assets
Beginning of period	4,196,732	6,456,644
End of period (including distributions in excess of net investment income of $117 and distributions in excess of net investment income of $116, respectively)	$ 3,387,550	$ 4,196,732

See accompanying notes which are an integral part of the financial statements.

Annual Report

Financial Highlights

Years ended April 30,	2012	2011	2010	2009	2008
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)	- D	- D	.002	.021	.045
Net realized and unrealized gain (loss) D	-	-	-	-	-
Total from investment operations	- D	- D	.002	.021	.045
Distributions from net investment income	- D	- D	(.002)	(.021)	(.045)
Distributions from net realized gain	-	- D	- D	-	-
Total distributions	- D	- D	(.002)	(.021)	(.045)
Net asset value, end of period	$ 1.00	$ 1.00	$ 1.00	$ 1.00	$ 1.00
Total Return A,B	.01%	.03%	.24%	2.10%	4.60%
Ratios to Average Net Assets C
Expenses before reductions	.42%	.42%	.43%	.44%	.42%
Expenses net of fee waivers, if any	.37%	.41%	.43%	.44%	.42%
Expenses net of all reductions	.37%	.41%	.43%	.44%	.41%
Net investment income (loss)	.01%	.03%	.26%	2.03%	4.49%
Supplemental Data
Net assets, end of period (in millions)	$ 3,388	$ 4,197	$ 6,457	$ 8,876	$ 7,790

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

^B Total returns do not include the effect of the account closeout fee.

^C Expense ratios reflect operating expenses of the Fund. Expenses before reductions do not reflect amounts reimbursed or waived or reductions from expense offset arrangements and do not represent the amount paid by the Fund during periods when reimbursements, waivers or reductions occur. Expenses net of fee waivers reflect expenses after reimbursement and waivers but prior to reductions from expense offset arrangements. Expenses net of all reductions represent the net expenses paid by the Fund.

^D Amount represents less than $.001 per share.

See accompanying notes which are an integral part of the financial statements.

Annual Report

Notes to Financial Statements

For the period ended April 30, 2012

(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.

2. Significant Accounting Policies.

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 following summarizes the significant accounting policies of the Fund:

Security 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 - 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. Interest income includes coupon interest and amortization of premium and accretion of discount on debt securities.

Annual Report

Notes to Financial Statements - continued

(Amounts in thousands except percentages)

2. Significant Accounting Policies - continued

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. 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), independent Trustees may elect to defer receipt of a portion of their annual compensation. Deferred amounts are invested in a cross-section of Fidelity funds, are marked-to-market and remain in the Fund until distributed in accordance with the Plan. The investment of deferred amounts and the offsetting payable to the Trustees are included in the accompanying Statement of Assets and Liabilities.

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 income taxes is required. As of April 30, 2012, 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. A 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.

Dividends 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.

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. Temporary book-tax differences will reverse in a subsequent period.

Book-tax differences are primarily due to deferred trustees compensation and capital loss carryforwards.

The federal tax cost of investment securities and unrealized appreciation (depreciation) as of period end were as follows:

Gross unrealized appreciation	$ -
Gross unrealized depreciation	-
Net unrealized appreciation (depreciation) on securities and other investments	$ -
Tax Cost	$ 3,392,359

Annual Report

2. Significant Accounting Policies - continued

Income Tax Information and Distributions to Shareholders - continued

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

Undistributed ordinary income	$ 39
Capital loss carryforward	$ (71)
Net unrealized appreciation (depreciation)	$ -

Capital loss carryforwards are only available to offset future capital gains of the Fund to the extent provided by regulations and may be limited. Under the Regulated Investment Company Modernization Act of 2010 (the Act), the Fund is permitted to carry forward capital losses incurred in taxable years beginning after December 22, 2010 for an unlimited period and such capital losses are required to be used prior to any losses that expire. Capital loss carryforwards were as follows:

Fiscal year of expiration
2019	$ (71)

The tax character of distributions paid was as follows:

	April 30, 2012	April 30, 2011
Ordinary Income	$ 389	$ 1,685

3. Operating Policies.

Repurchase Agreements. Fidelity Management & Research Company (FMR) has received an Exemptive Order from the Securities and Exchange Commission (the SEC) which permits the Fund and other affiliated entities of FMR to transfer uninvested cash balances into joint trading accounts which are then invested in repurchase agreements. The Fund may also invest directly with institutions in repurchase agreements. Repurchase agreements are collateralized by government or non-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 Fund monitors, on a daily basis, the value of the collateral 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.

Annual Report

Notes to Financial Statements - continued

(Amounts in thousands except percentages)

3. Operating Policies - continued

Reverse Repurchase Agreements. To enhance its yield, the Fund may enter into reverse repurchase agreements whereby the Fund transfers securities to a counterparty who then agrees to transfer them back to the Fund at a future date and agreed upon price, reflecting a rate of interest below market rate. Securities sold under a reverse repurchase agreement, if any, are recorded as a liability in the accompanying Statement of Assets and Liabilities. The Fund receives cash proceeds, which are invested in other securities, and agrees to repay the proceeds plus any accrued interest in return for the same securities transferred. The Fund continues to receive interest payments on the transferred securities during the term of the reverse repurchase agreement. During the period that a reverse repurchase agreement is outstanding, the Fund identifies cash and liquid securities as segregated in its custodian records with a value at least equal to its obligation under the agreement. If the counterparty defaults on its obligation, because of insolvency or other reasons, the Fund could experience delays and costs in recovering the security or in gaining access to the collateral. The average balance during the period for which reverse repurchase agreements were outstanding subject to interest amounted to $1,999. The weighted average interest rate was .05% on such amounts. Information regarding reverse repurchase agreements open at period end is included at the end of the Fund's Schedule of Investments.

Restricted Securities. The Fund 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 is included at the end of the Fund's Schedule of Investments.

4. Fees and Other Transactions with Affiliates.

Management Fee. FMR 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. FMR pays all other expenses, except the compensation of the independent Trustees and certain exceptions such as interest expense. The management fee paid to FMR by the Fund is reduced by an amount equal to the fees and expenses paid by the Fund to the independent Trustees.

Annual Report

5. Expense Reductions.

FMR or its affiliates voluntarily agreed to waive certain fees in order to maintain a minimum annualized yield of .01%. Such arrangements may be discontinued by FMR at any time. For the period, the amount of the waiver was $1,732.

In addition, through arrangements with the Fund's custodian, credits realized as a result of uninvested cash balances were used to reduce the Fund's management fee. During the period, these credits reduced the Fund's management fee by eighty-four dollars.

6. Other.

The 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, the Fund may also enter into contracts that provide general indemnifications. The Fund's maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against the Fund. The risk of material loss from such claims is considered remote.

Annual Report

Report of Independent Registered Public Accounting Firm

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

In our opinion, the accompanying statement of assets and liabilities, including the schedule of investments, and the related statements of operations and of changes in net assets and the financial highlights present fairly, in all material respects, the financial position of Fidelity Money Market Fund (a fund of Fidelity Hereford Street Trust) at April 30, 2012, 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 five years in the period then ended, in conformity with accounting principles generally accepted in the United States of America. These financial statements and financial highlights (hereafter referred to as "financial statements") are the responsibility of the Fidelity Money Market Fund's management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits, which included confirmation of securities at April 30, 2012 by correspondence with the custodian and brokers, provide a reasonable basis for our opinion.

PricewaterhouseCoopers LLP

Boston, Massachusetts

June 7, 2012

Annual Report

Trustees and Officers

The Trustees and executive 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. Except for Mr. Curvey, each of the Trustees oversees 207 funds advised by FMR or an affiliate. Mr. Curvey oversees 435 funds advised by FMR or an affiliate.

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) (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. The executive officers hold office without limit in time, except that any officer 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.

Experience, Skills, Attributes, and Qualifications of the Fund's 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.

Annual Report

Trustees and Officers - continued

Board Structure and Oversight Function. Abigail P. Johnson is an interested person (as defined in the 1940 Act) 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. Kenneth L. Wolfe 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, and asset allocation funds and another Board oversees Fidelity's equity and high income funds. The asset allocation funds may invest in Fidelity funds that are overseen by such other Board. 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 FMR'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 Fund's Trustees."

Annual Report

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 each Trustee who is an interested person may be sent to Fidelity Investments, 82 Devonshire Street, Boston, Massachusetts 02109.

Name, Age; Principal Occupations and Other Relevant Experience+
Abigail P. Johnson (50)
	Year of Election or Appointment: 2009 Ms. Johnson is Trustee and Chairman of the Board of Trustees of certain Trusts. Ms. Johnson serves as President of Personal, Workplace and Institutional Services (2005-present). Ms. Johnson is Chairman and Director of FMR Co., Inc. (2011-present), Chairman and Director of FMR (2011-present), and the Vice Chairman and Director (2007-present) of FMR LLC. Previously, Ms. Johnson served as President and a Director of FMR (2001-2005), a Trustee of other investment companies advised by FMR, Fidelity Investments Money Management, Inc., 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.
James C. Curvey (76)
	Year of Election or Appointment: 2007 Mr. Curvey also serves as Trustee (2007-present) of other investment companies advised by FMR. Mr. Curvey is a Director of Fidelity Investments Money Management, Inc. (2009-present), Director of Fidelity Research & Analysis Co. (2009-present) and Director of FMR and FMR Co., Inc. (2007-present). Mr. Curvey is also Vice Chairman (2007-present) and Director of FMR LLC. In addition, Mr. Curvey serves as an Overseer for the Boston Symphony Orchestra and a member of the Trustees of Villanova University. Previously, Mr. Curvey was the Vice Chairman (2006-2007) and Director (2000-2007) of FMR Corp.

* Trustees have been determined to be "Interested Trustees" by virtue of, among other things, their affiliation with the trust or various entities under common control with FMR.

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

Independent Trustees:

Correspondence intended for each Independent Trustee (that is, the Trustees other than the Interested Trustees) may be sent to Fidelity Investments, P.O. Box 55235, Boston, Massachusetts 02205-5235.

Name, Age; Principal Occupations and Other Relevant Experience+
Albert R. Gamper, Jr. (70)
	Year of Election or Appointment: 2006 Mr. Gamper is Vice Chairman of the Independent Trustees of the Fixed Income and Asset Allocation Funds (2011-present). Prior to his retirement in December 2004, Mr. Gamper served as Chairman of the Board of CIT Group Inc. (commercial finance). During his tenure with CIT Group Inc. Mr. Gamper served in numerous senior management positions, including Chairman (1987-1989; 1999-2001; 2002-2004), Chief Executive Officer (1987-2004), and President (2002-2003). Mr. Gamper currently serves as a member of the Board of Directors of Public Service Enterprise Group (utilities, 2000-present), a member of the Board of Trustees, Rutgers University (2004-present), and Chairman of the Board of Saint Barnabas Health Care System. Previously, Mr. Gamper served as Chairman of the Board of Governors, Rutgers University (2004-2007).
Robert F. Gartland (60)
	Year of Election or Appointment: 2010 Mr. Gartland is Chairman and an investor in Gartland and Mellina Group Corp. (consulting, 2009-present). Previously, Mr. Gartland served as a partner and investor of Vietnam Partners LLC (investments and consulting, 2008-2011). Prior to his retirement, Mr. Gartland held a variety of positions at Morgan Stanley (financial services, 1979-2007) including Managing Director (1987-2007).
Arthur E. Johnson (65)
	Year of Election or Appointment: 2008 Mr. Johnson serves as a member of the Board of Directors of Eaton Corporation (diversified power management, 2009-present), AGL Resources, Inc. (holding company, 2002-present) and Booz Allen Hamilton (management consulting, 2011-present). Prior to his retirement, Mr. Johnson served as Senior Vice President of Corporate Strategic Development of Lockheed Martin Corporation (defense contractor, 1999-2009). He previously served on the Board of Directors of IKON Office Solutions, Inc. (1999-2008) and Delta Airlines (2005-2007). Mr. Arthur E. Johnson is not related to Mr. Edward C. Johnson 3d or Ms. Abigail P. Johnson.
Michael E. Kenneally (58)
	Year of Election or Appointment: 2009 Previously, Mr. Kenneally served as a Member of the Advisory Board for certain Fidelity Fixed Income and Asset Allocation Funds (2008-2009). Prior to his retirement, Mr. Kenneally served as Chairman and Global Chief Executive Officer of Credit Suisse Asset Management (2003-2005). Mr. Kenneally was a Director of the Credit Suisse Funds (U.S. mutual funds, 2004-2008) and certain other closed-end funds (2004-2005) and was awarded the Chartered Financial Analyst (CFA) designation in 1991.
James H. Keyes (71)
	Year of Election or Appointment: 2007 Mr. Keyes serves as a member of the Boards of Navistar International Corporation (manufacture and sale of trucks, buses, and diesel engines, since 2002) and Pitney Bowes, Inc. (integrated mail, messaging, and document management solutions, since 1998). Prior to his retirement, Mr. Keyes served as Chairman and Chief Executive Officer of Johnson Controls (automotive, building, and energy, 1998-2002) and as a member of the Board of LSI Logic Corporation (semiconductor technologies, 1984-2008).
Marie L. Knowles (65)
	Year of Election or Appointment: 2001 Prior to Ms. Knowles' retirement in June 2000, she served as Executive Vice President and Chief Financial Officer of Atlantic Richfield Company (ARCO) (diversified energy, 1996-2000). From 1993 to 1996, she was a Senior Vice President of ARCO and President of ARCO Transportation Company. She served as a Director of ARCO from 1996 to 1998. Ms. Knowles currently serves as a Director and Chairman of the Audit Committee of McKesson Corporation (healthcare service, since 2002). Ms. Knowles is an Honorary Trustee of the Brookings Institution and a member of the Board of the Catalina Island Conservancy and of the Santa Catalina Island Company (2009-present). She also serves as a member of the Advisory Board for the School of Engineering of the University of Southern California and the Foundation Board of the School of Architecture at the University of Virginia (2007-present). Previously, Ms. Knowles served as a Director of Phelps Dodge Corporation (copper mining and manufacturing, 1994-2007).
Kenneth L. Wolfe (73)
	Year of Election or Appointment: 2005 Mr. Wolfe is Chairman of the Independent Trustees of the Fixed Income and Asset Allocation Funds (2008-present). Prior to his retirement, Mr. Wolfe served as Chairman and a Director (2007-2009) and Chairman and Chief Executive Officer (1994-2001) of Hershey Foods Corporation. He also served as a member of the Boards of Adelphia Communications Corporation (telecommunications, 2003-2006), Bausch & Lomb, Inc. (medical/pharmaceutical, 1993-2007), and Revlon, Inc. (personal care products, 2004-2009).

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

Annual Report

Executive Officers:

Correspondence intended for each executive officer may be sent to Fidelity Investments, 82 Devonshire Street, Boston, Massachusetts 02109.

Name, Age; Principal Occupation
John R. Hebble (53)
	Year of Election or Appointment: 2008 President and Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Hebble also serves as President (2011-present), Treasurer, and Chief Financial Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present), Assistant Treasurer of other Fidelity funds (2009-present) and is an employee of Fidelity Investments.
Robert P. Brown (48)
	Year of Election or Appointment: 2010 Vice President of Fidelity's Money Market Funds and Executive Vice President of Fidelity Investments Money Management, Inc. (2010-present). Mr. Brown also serves as President, Money Market Group of FMR (2010-present), Managing Director of Research, Director of Fidelity Management & Research (U.K.) Inc. (2008-present) and is an employee of Fidelity Investments.
Scott C. Goebel (44)
	Year of Election or Appointment: 2008 Secretary and Chief Legal Officer (CLO) of the Fidelity funds. Mr. Goebel also serves as Secretary of Fidelity Investments Money Management, Inc. (FIMM) (2010-present) and Fidelity Research and Analysis Company (FRAC) (2010-present); Secretary and CLO of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present); General Counsel, Secretary, and Senior Vice President of FMR (2008-present) and FMR Co., Inc. (2008-present); employed by FMR LLC or an affiliate (2001-present); Chief Legal Officer of Fidelity Management & Research (Hong Kong) Limited (2008-present) and Assistant Secretary of Fidelity Management & Research (Japan) Inc. (2008-present), and Fidelity Management & Research (U.K.) Inc. (2008-present). Previously, Mr. Goebel served as Assistant Secretary of FIMM (2008-2010), FRAC (2008-2010), and the Funds (2007-2008) and as Vice President and Secretary of Fidelity Distributors Corporation (FDC) (2005-2007).
David J. Carter (38)
	Year of Election or Appointment: 2010 Assistant Secretary of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Carter also serves as Vice President, Associate General Counsel (2010-present) and is an employee of Fidelity Investments (2005-present).
Elizabeth Paige Baumann (43)
	Year of Election or Appointment: 2012 Anti-Money Laundering (AML) Officer of the Fidelity funds. Ms. Baumann also serves as AML Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2012-present), Chief AML Officer of FMR LLC (2012-present), and is an employee of Fidelity Investments. Previously, Ms. Baumann served as Vice President and Deputy Anti-Money Laundering Officer (2007-2012).
Christine Reynolds (53)
	Year of Election or Appointment: 2008 Chief Financial Officer of the Fidelity funds. Ms. Reynolds became President of Fidelity Pricing and Cash Management Services (FPCMS) in August 2008. Ms. Reynolds served as Chief Operating Officer of FPCMS (2007-2008). Previously, Ms. Reynolds served as President, Treasurer, and Anti-Money Laundering officer of the Fidelity funds (2004-2007).
Michael H. Whitaker (44)
	Year of Election or Appointment: 2008 Chief Compliance Officer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Whitaker also serves as Chief Compliance Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2008-present). Mr. Whitaker is an employee of Fidelity Investments (2007-present). Prior to joining Fidelity Investments, Mr. Whitaker worked at MFS Investment Management where he served as Senior Vice President and Chief Compliance Officer (2004-2006), and Assistant General Counsel.
Joseph F. Zambello (54)
	Year of Election or Appointment: 2011 Deputy Treasurer of the Fidelity funds. Mr. Zambello is an employee of Fidelity Investments. Previously, Mr. Zambello served as Vice President of FMR's Program Management Group (2009-2011) and Vice President of the Transfer Agent Oversight Group (2005-2009).
Stephanie J. Dorsey (42)
	Year of Election or Appointment: 2008 Deputy Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Ms. Dorsey also serves as Assistant Treasurer of other Fidelity funds (2010-present) and is an employee of Fidelity Investments (2008-present). Previously, Ms. Dorsey served as Treasurer (2004-2008) of the JPMorgan Mutual Funds and Vice President (2004-2008) of JPMorgan Chase Bank.
Adrien E. Deberghes (44)
	Year of Election or Appointment: 2010 Assistant Treasurer of Fidelity's Fixed Income and Asset Allocation Funds. Mr. Deberghes also serves as Vice President and Assistant Treasurer (2011-present) and Deputy Treasurer (2008-present) of other Fidelity funds, and is an employee of Fidelity Investments (2008-present). Previously, Mr. Deberghes served as Senior Vice President of Mutual Fund Administration at State Street Corporation (2007-2008), Senior Director of Mutual Fund Administration at Investors Bank & Trust (2005-2007), and Director of Finance for Dunkin' Brands (2000-2005).
Kenneth B. Robins (42)
	Year of Election or Appointment: 2009 Assistant Treasurer of the Fidelity Fixed Income and Asset Allocation Funds. Mr. Robins also serves as President and Treasurer of other Fidelity funds (2008-present; 2010-present) and is an employee of Fidelity Investments (2004-present). Previously, Mr. Robins served as Deputy Treasurer of the Fidelity funds (2005-2008) and Treasurer and Chief Financial Officer of The North Carolina Capital Management Trust: Cash and Term Portfolios (2006-2008).
Gary W. Ryan (53)
	Year of Election or Appointment: 2005 Assistant Treasurer of the Fidelity funds. Mr. Ryan is an employee of Fidelity Investments. Previously, Mr. Ryan served as Vice President of Fund Reporting in Fidelity Pricing and Cash Management Services (FPCMS) (1999-2005).
Jonathan Davis (43)
	Year of Election or Appointment: 2010 Assistant Treasurer of the Fidelity funds. Mr. Davis is also Assistant Treasurer of Fidelity Rutland Square Trust II and Fidelity Commonwealth Trust II. Mr. Davis is an employee of Fidelity Investments. Previously, Mr. Davis served as Vice President and Associate General Counsel of FMR LLC (2003-2010).

Annual Report

Distributions (Unaudited)

A total of 4.78% 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 $122,517 of distributions paid during the period January 1, 2012 to April 30, 2012 as qualifying to be taxed as interest-related dividends for nonresident alien shareholders.

The fund will notify shareholders in January 2013 of amounts for use in preparing 2012 income tax returns.

Annual Report

Investment Adviser

Fidelity Management & Research Company

Boston, MA

Investment Sub-Advisers

Fidelity Investments
Money Management, Inc.

Fidelity Management & Research
(Hong Kong) Limited

Fidelity Management & Research
(Japan) Inc.

Fidelity Management & Research
(U.K.) Inc.

General Distributor

Fidelity Distributors Corporation

Boston, MA

Transfer and Service Agents

Fidelity Investments Institutional
Operations Company, Inc.

Boston, MA

Fidelity Service Company, Inc.

Boston, MA

Custodian

JPMorgan Chase Bank

New York, NY

The Fidelity Telephone Connection

Mutual Fund 24-Hour Service

Exchanges/Redemptions
and Account Assistance 1-800-544-6666

Product Information 1-800-544-6666

Retirement Accounts 1-800-544-4774
(8 a.m. - 9 p.m.)

TDD Service 1-800-544-0118
for the deaf and hearing impaired
(9 a.m. - 9 p.m. Eastern time)

Fidelity Automated Service
Telephone (FAST®)
1-800-544-5555

Automated line for quickest service

(Fidelity Investment logo)(registered trademark)
Corporate Headquarters
82 Devonshire St., Boston, MA 02109
www.fidelity.com

SPM-UANN-0612
1.784732.109

Item 2. Code of Ethics

As of the end of the period, April 30, 2012, Fidelity Hereford Street Trust (the trust) has adopted a code of ethics, as defined in Item 2 of Form N-CSR, that applies to its President and Treasurer and its Chief Financial Officer. A copy of the code of ethics is filed as an exhibit to this Form N-CSR.

Item 3. Audit Committee Financial Expert

The Board of Trustees of the trust has determined that Marie L. Knowles is an audit committee financial expert, as defined in Item 3 of Form N-CSR.   Ms. Knowles is independent for purposes of Item 3 of Form N-CSR.  

Item 4. Principal Accountant Fees and Services

Fees and Services

The following table presents fees billed by PricewaterhouseCoopers LLP ("PwC") in each of the last two fiscal years for services rendered to Fidelity Government Money Market Fund, Fidelity Money Market Fund and Fidelity U.S. Treasury Money Market Fund (the "Funds"):

Services Billed by PwC

April 30, 2012 Fees^A

	Audit Fees	Audit-Related Fees	Tax Fees	All Other Fees
Fidelity Government Money Market Fund	$39,000	$-	$2,000	$1,900
Fidelity Money Market Fund	$43,000	$-	$2,000	$3,200
Fidelity U.S. Treasury Money Market Fund	$45,000	$-	$2,000	$4,000

April 30, 2011 Fees^A

	Audit Fees	Audit-Related Fees	Tax Fees	All Other Fees
Fidelity Government Money Market Fund	$42,000	$-	$2,000	$2,000
Fidelity Money Market Fund	$49,000	$-	$2,000	$4,700
Fidelity U.S. Treasury Money Market Fund	$48,000	$-	$2,000	$4,200

^A Amounts may reflect rounding.

The following table presents fees billed by PwC that were required to be approved by the Audit Committee for services that relate directly to the operations and financial reporting of the Funds and that are rendered on behalf of Fidelity Management & Research Company ("FMR") and entities controlling, controlled by, or under common control with FMR (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser) that provide ongoing services to the Funds ("Fund Service Providers"):

Services Billed by PwC

	April 30, 2012A	April 30, 2011A
Audit-Related Fees	$3,795,000	$2,535,000
Tax Fees	$-	$-
All Other Fees	$-	$365,000

^A Amounts may reflect rounding.

"Audit-Related Fees" represent fees billed for assurance and related services that are reasonably related to the performance of the fund audit or the review of the fund's financial statements and that are not reported under Audit Fees.

"Tax Fees" represent fees billed for tax compliance, tax advice or tax planning that relate directly to the operations and financial reporting of the fund.

"All Other Fees" represent fees billed for services provided to the fund or Fund Service Provider, a significant portion of which are assurance related, that relate directly to the operations and financial reporting of the fund, excluding those services that are reported under Audit Fees, Audit-Related Fees or Tax Fees.

Assurance services must be performed by an independent public accountant.

* * *

The aggregate non-audit fees billed by PwC for services rendered to the Funds, FMR (not including any sub-adviser whose role is primarily portfolio management and is subcontracted with or overseen by another investment adviser), and any Fund Service Provider for each of the last two fiscal years of the Funds are as follows:

Billed By	April 30, 2012 A	April 30, 2011 A
PwC	$5,060,000	$4,720,000

^A Amounts may reflect rounding.

The trust's Audit Committee has considered non-audit services that were not pre-approved that were provided by PwC to Fund Service Providers to be compatible with maintaining the independence of PwC in its audit of the Funds, taking into account representations from PwC, in accordance with Public Company Accounting Oversight Board rules, regarding its independence from the Funds and their related entities and FMR's review of the appropriateness and permissibility under applicable law of such non-audit services prior to their provision to the Fund Service Providers.

Audit Committee Pre-Approval Policies and Procedures

The trust's Audit Committee must pre-approve all audit and non-audit services provided by a fund's independent registered public accounting firm relating to the operations or financial reporting of the fund. Prior to the commencement of any audit or non-audit services to a fund, the Audit Committee reviews the services to determine whether they are appropriate and permissible under applicable law.

The Audit Committee has adopted policies and procedures to, among other purposes, provide a framework for the Committee's consideration of non-audit services by the audit firms that audit the Fidelity funds. The policies and procedures require that any non-audit service provided by a fund audit firm to a Fidelity fund and any non-audit service provided by a fund auditor to a Fund Service Provider that relates directly to the operations and financial reporting of a Fidelity fund ("Covered Service") are subject to approval by the Audit Committee before such service is provided.

All Covered Services must be approved in advance of provision of the service either: (i) by formal resolution of the Audit Committee, or (ii) by oral or written approval of the service by the Chair of the Audit Committee (or if the Chair is unavailable, such other member of the Audit Committee as may be designated by the Chair to act in the Chair's absence). The approval contemplated by (ii) above is permitted where the Treasurer determines that action on such an engagement is necessary before the next meeting of the Audit Committee.

Non-audit services provided by a fund audit firm to a Fund Service Provider that do not relate directly to the operations and financial reporting of a Fidelity fund are reported to the Audit Committee on a periodic basis.

Non-Audit Services Approved Pursuant to Rule 2-01(c)(7)(i)(C) and (ii) of Regulation S-X ("De Minimis Exception")

There were no non-audit services approved or required to be approved by the Audit Committee pursuant to the De Minimis Exception during the Funds' last two fiscal years relating to services provided to (i) the Funds or (ii) any Fund Service Provider that relate directly to the operations and financial reporting of the Funds.

Item 5. Audit Committee of Listed Registrants

Not applicable.

Item 6. Investments

(a) Not applicable.

(b) Not applicable

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies

Not applicable.

Item 8. Portfolio Managers of Closed-End Management Investment Companies

Not applicable.

Item 9. Purchase of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers

Not applicable.

Item 10. Submission of Matters to a Vote of Security Holders

There were no material changes to the procedures by which shareholders may recommend nominees to the trust's Board of Trustees.

Item 11. Controls and Procedures

(a)(i) The President and Treasurer and the Chief Financial Officer have concluded that the trust's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act) provide reasonable assurances that material information relating to the trust is made known to them by the appropriate persons, based on their evaluation of these controls and procedures as of a date within 90 days of the filing date of this report.

(a)(ii) There was no change in the trust's internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act) that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the trust's internal control over financial reporting.

Item 12. Exhibits

(a)	(1)	Code of Ethics pursuant to Item 2 of Form N-CSR is filed and attached hereto as EX-99.CODE ETH.
(a)	(2)	Certification pursuant to Rule 30a-2(a) under the Investment Company Act of 1940 (17 CFR 270.30a-2(a)) is filed and attached hereto as Exhibit 99.CERT.
(a)	(3)	Not applicable.
(b)		Certification pursuant to Rule 30a-2(b) under the Investment Company Act of 1940 (17 CFR 270.30a-2(b)) is furnished and attached hereto as Exhibit 99.906CERT.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Fidelity Hereford Street Trust

By:	/s/John R. Hebble
	John R. Hebble
	President and Treasurer
Date:	June 27, 2012

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By:	/s/John R. Hebble
	John R. Hebble
	President and Treasurer
Date:	June 27, 2012

By:	/s/Christine Reynolds
	Christine Reynolds
	Chief Financial Officer
Date:	June 27, 2012