N-CSR

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 811-02945

Centennial Money Market Trust

(Exact name of registrant as specified in charter)

6803 South Tucson Way, Centennial, Colorado 80112-3924
(Address of principal executive offices) (Zip code)

Robert G. Zack, Esq.
OppenheimerFunds, Inc.
Two World Financial Center, New York, New York 10281-1008
(Name and address of agent for service)

Registrant’s telephone number, including area code: (303) 768-3200

Date of fiscal year end: June 30

Date of reporting period: 06/30/2009

Item 1. Reports to Stockholders.

June 30, 2009 Centennial Money Market            Annual Report Trust

LETTER TO SHAREHOLDERS

Dear Shareholder,

We are pleased to provide this annual report for Centennial Money Market Trust. During the 12-month reporting period ended June 30, 2009, the Trust produced a 0.91% yield with and without compounding. As of June 30, 2009, the Trust’s 7-day yield was 0.01% with and without compounding.

     The performance data quoted represents past performance, which does not guarantee future results. Yields include the reinvestment of dividends in a hypothetical investment for the periods shown. Current performance may be lower or higher than the performance quoted. For performance data current to the most recent month end, contact Shareholder Services, Inc. at 1.800.525.9310. The Trust’s performance shown does not reflect the deduction of income taxes on an individual’s investment. Without a voluntary expense limit that can be terminated at any time, Trust performance may have been less. Taxes may reduce your actual investment returns on income paid by the Trust.

Sincerely,

John V. Murphy
President
Centennial Money Market Trust
July 22, 2009

In reviewing performance, please remember that past performance cannot guarantee future results. Yields will fluctuate. An investment in the Trust is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Although the Trust seeks to preserve the value of your investment at $1.00 per share, it is possible to lose money by investing in the Trust.

2 | CENTENNIAL MONEY MARKET TRUST

TRUST EXPENSES

Trust Expenses. As a shareholder of the Trust, you incur ongoing costs, including management fees; service fees; and other Trust expenses. These examples are intended to help you understand your ongoing costs (in dollars) of investing in the Trust and to compare these costs with the ongoing costs of investing in other mutual funds.

The examples are based on an investment of $1,000.00 invested at the beginning of the period and held for the entire 6-month period ended June 30, 2009.

Actual Expenses. The first section of the table provides information about actual account values and actual expenses. You may use the information in this section, together with the amount you invested, to estimate the expense that you paid over the period. Simply divide your account value by $1,000.00 (for example, an $8,600.00 account value divided by $1,000.00 = 8.60), then multiply the result by the number in the first section under the heading entitled “Expenses Paid During Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes. The second section of the table provides information about hypothetical account values and hypothetical expenses based on the Trust’s actual expense ratio, and an assumed rate of return of 5% per year before expenses, which is not the actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Trust 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.

3 | CENTENNIAL MONEY MARKET TRUST

TRUST EXPENSES Continued

	Beginning		Ending		Expenses
	Account		Account		Paid During
	Value		Value		6 Months Ended
Actual	January 1, 2009		June 30, 2009		June 30, 2009
	$	1,000.00	$	1,000.50	$	2.78
Hypothetical (5% return before expenses)
		1,000.00		1,022.02		2.81

Expenses are equal to the Trust’s annualized expense ratio, multiplied by the average account value over the period, multiplied by 181/365 (to reflect the one-half year period). The annualized expense ratio based on the 6-month period ended June 30, 2009 is as follows:

Expense Ratio

0.56%

The expense ratio reflects voluntary waivers or reimbursements of expenses by the Trust’s Manager that can be terminated at any time, without advance notice. The “Financial Highlights” table in the Trust’s financial statements, included in this report, also shows the gross expense ratio, without such waivers or reimbursements and reduction to custodian expenses, if applicable.

4 | CENTENNIAL MONEY MARKET TRUST

STATEMENT OF INVESTMENTS June 30, 2009

	Principal
	Amount		Value
Certificates of Deposit—15.6%
Bank of Montreal, Chicago, 0.34%, 9/16/09	$	31,000,000	$	31,000,000
BNP Paribas, New York:
0.34%, 9/23/09		33,000,000		33,000,000
0.58%, 7/29/09		4,000,000		4,000,000
Calyon, New York, 0.25%, 7/17/09		23,200,000		23,200,000
National Australia Bank, New York, 0.32%, 9/24/09		48,000,000		48,000,000
Societe Generale, New York, 0.605%, 8/3/09		5,000,000		5,000,023
Westpac Banking Corp., New York, 0.33%, 9/17/09		65,000,000		65,000,000
Total Certificates of Deposit (Cost $209,200,023)				209,200,023
Direct Bank Obligations—25.7%
Bank of Nova Scotia, 0.31%, 8/10/09		29,000,000		28,990,011
Calyon North America, Inc., 0.27%, 7/6/09		31,500,000		31,499,017
CBA (Delaware) Finance, 0.45%, 8/4/09		65,700,000		65,671,914
Danske Corp., 0.26%, 7/13/091		66,200,000		66,194,165
Intesa Funding LLC, 0.30%, 7/20/09		50,000,000		49,992,083
National Australia Funding (Delaware), Inc.:
0.42%, 7/24/091		13,100,000		13,096,485
0.54%, 7/1/091		7,000,000		7,000,000
Nordea North America, Inc.:
0.25%, 7/13/09		6,000,000		5,999,500
0.30%, 8/19/09		6,800,000		6,797,223
0.30%, 9/4/09		7,000,000		6,996,208
Rabobank USA Financial Corp.:
0.30%, 8/19/09		12,500,000		12,494,896
0.50%, 12/8/09		50,000,000		49,888,889
Total Direct Bank Obligations (Cost $344,620,391)				344,620,391
Short-Term Notes—58.7%
Capital Markets—2.2%
BNP Paribas Finance, Inc., 0.29%, 8/20/09	$	29,500,000		29,488,118
Diversified Financial Services—2.3%
General Electric Capital Corp., 0.23%, 7/22/09		11,000,000		10,998,524
General Electric Capital Services:
0.37%, 9/1/09		13,500,000		13,491,398
0.55%, 7/28/09		6,200,000		6,197,443
				30,687,365
Food Products—1.8%
Nestle Capital Corp., 0.50%, 3/15/101		24,400,000		24,312,906
Insurance—8.1%
Jackson National Life Global Funding, Series 2004-6, 0.429%, 8/15/092,3		50,000,000		50,000,000
MetLife Funding, Inc.:
0.30%, 7/22/09		24,465,000		24,460,719
0.35%, 7/9/09		35,000,000		34,997,278
				109,457,997
Leasing & Factoring—6.6%
American Honda Finance Corp., 0.811%, 8/26/093,4		50,000,000		50,022,613
Toyota Motor Credit Corp.:
0.26%, 7/21/09		21,500,000		21,496,894
0.28%, 7/29/09		11,700,000		11,697,452
0.30%, 7/27/09		5,000,000		4,998,917
				88,215,876

F1 | CENTENNIAL MONEY MARKET TRUST

STATEMENT OF INVESTMENTS Continued

	Principal
	Amount		Value
Municipal—4.1%
Arlington Cnty., VA Industrial Development Authority Economic Development Revenue Bonds, Skating Facilities, Series 2005, 0.90%, 7/1/093	$	2,300,000	$	2,300,000
Ashland, WI Industrial Development Revenue Bonds, Larson-Juhl US LLC Project, Series 2000, 0.62%, 7/1/093		3,750,000		3,750,000
Davidson Cnty. Industrial Facility & Pollution Control Finance Authority, Diebold, Inc. Project, Series 1997, 0.55%, 7/1/093		2,660,000		2,660,000
District of Columbia Bonds, The Pew Charitable Trusts Issue, Series 2008B, 0.74%, 7/1/093		1,300,000		1,300,000
Fredericksburg, VA Economic Development Bonds, Eagle Village, Series 2009B, 0.60%, 7/1/093		10,000,000		10,000,000
Muskogee, OK Trust Port Authority Industrial Development Revenue Bonds, Uni-Steel, Inc., Series 1998, 0.57%, 7/1/093		2,850,000		2,850,000
NJ Healthcare Facilities Finance Authority Revenue Bonds, St. Peter’s University Hospital, Series 2000C, 0.60%, 7/1/093		1,670,000		1,670,000
NJ Housing and Mortgage Finance Agency Multifamily Revenue Bonds, Series 2008G, 0.55%, 11/1/093		1,500,000		1,500,000
SC Jobs-Economic Development Authority Bonds, Abraham Industries LLC Project, Series 1999, 0.80%, 7/1/093		2,025,000		2,025,000
SC Jobs-Economic Development Authority Bonds, South Atlantic Canners, Inc., Series 2001, 0.57%, 9/1/093		5,000,000		5,000,000
Shaw University Bonds, Series A, 0.70%, 7/1/093		1,965,000		1,965,000
WA Economic Development Finance Authority Industrial Development Revenue Bonds, Canam Steel Corp. Project, Series 2000D, 0.55%, 7/1/093		4,000,000		4,000,000
Walton Cnty. Development Authority Industrial Development Revenue Bonds, Walton Press, Inc., Series 2006, 0.55%, 7/1/093		3,360,000		3,360,000

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	Principal
	Amount			Value
Municipal Continued
Washington Cnty., PA Industrial Development Authority Bonds, AccuTrex Products, Inc. Project, Series 1996, 0.80%, 7/1/093	$	1,000,000		$	1,000,000
Whitehall, WI Industrial Development Revenue Bonds, Whitehall Specialties, 0.50%, 7/1/093		5,400,000			5,400,000
Winston-Salem, NC Certificates of Participation, Series 1992, 0.65%, 7/1/093		6,250,000			6,250,000
					55,030,000
Personal Products—2.5%
Reckitt Benckiser Treasury Services plc:
0.24%, 7/10/091		14,300,000			14,299,142
0.40%, 8/3/091		4,000,000			3,998,533
0.53%, 9/11/091		15,000,000			14,984,100
					33,281,775
Receivables Finance—25.6%
Barton Capital Corp.:
0.25%, 7/8/091		23,700,000			23,698,387
0.35%, 7/7/091		37,979,000			37,976,729
0.35%, 8/12/091		8,000,000			7,996,733
Fairway Finance Corp.:
0.35%, 9/1/091		2,000,000			1,998,794
0.37%, 9/14/091		6,389,000			6,384,075
0.38%, 9/9/091		5,300,000			5,296,187
Falcon Asset Securitization Co. LLC, 0.37%, 8/7/091		45,000,000			44,982,888
Gemini Securitization Corp.:
0.55%, 7/15/091		4,000,000			3,999,144
0.57%, 7/17/091		6,200,000			6,198,429
Kitty Hawk Funding Corp., 0.45%, 7/14/091		3,150,000			3,149,488
Legacy Capital LLC:
0.55%, 7/9/09		6,000,000			5,999,267
0.65%, 8/6/09		3,500,000			3,497,725
Old Line Funding Corp.:
0.35%, 9/10/091		10,000,000			9,993,097
0.35%, 9/15/091		7,700,000			7,694,636
0.36%, 8/11/091		15,000,000			14,993,850
0.36%, 8/17/091		7,350,000			7,346,546
0.45%, 8/7/091		30,000,000			29,986,125
Park Avenue Receivables Co. LLC:
0.25%, 8/19/09		15,300,000			15,294,794
0.37%, 8/6/09		50,000,000			49,981,500
Ranger Funding Co. LLC, 0.45%, 7/14/094		9,020,000			9,018,534
Thunder Bay Funding LLC:
0.32%, 9/1/094		16,400,000			16,390,397
0.35%, 8/17/094		18,000,000			17,991,775
0.35%, 9/15/094		14,500,000			14,489,286
					344,358,386
Special Purpose Financial—5.5%
FCAR Owner Trust I, 1.15%, 7/1/09		13,500,000			13,500,000
Straight-A Funding, Series I, 0.37%, 9/8/09		50,000,000			49,964,542
Ticonderoga Funding LLC, 0.26%, 7/22/09		10,704,000			10,702,064
					74,166,606
Total Short-Term Notes (Cost $788,999,029)					788,999,029
Total Investments, at Value (Cost $1,342,819,443)		100.0	%		1,342,819,443
Liabilities in Excess of Other Assets		(0.0	)		(164,229	)
Net Assets		100.0	%	$	1,342,655,214

F3 | CENTENNIAL MONEY MARKET TRUST

STATEMENT OF INVESTMENTS Continued

Footnotes to Statement of Investments

Short-term notes and direct bank obligations are generally traded on a discount basis; the interest rate shown is the discount rate received by the Trust at the time of purchase. Other securities normally bear interest at the rates shown.

1.	Security issued in an exempt transaction without registration under the Securities Act of 1933. Such securities amount to $355,580,439, or 26.48% of the Trust’s net assets, and have been determined to be liquid pursuant to guidelines adopted by the Board of Trustees.
2.	Illiquid security. The aggregate value of illiquid securities as of June 30, 2009 was $50,000,000, which represents 3.72% of the Trust’s net assets. See Note 4 of accompanying Notes.
3.	Represents the current interest rate for a variable or increasing rate security.
4.	Represents securities sold under Rule 144A, which are exempt from registration under the Securities Act of 1933, as amended. These securities have been determined to be liquid under guidelines established by the Board of Trustees. These securities amount to $107,912,605 or 8.04% of the Trust’s net assets as of June 30, 2009.

Valuation Inputs

Various data inputs are used in determining the value of each of the Trust’s investments as of the reporting period end. These data inputs are categorized in the following hierarchy under applicable financial accounting standards:

1) Level 1-unadjusted quoted prices in active markets for identical assets or liabilities (including securities actively traded on a securities exchange)

2) Level 2-inputs other than unadjusted quoted prices that are observable for the asset (such as unadjusted quoted prices for similar assets and market corroborated inputs such as interest rates, prepayment speeds, credit risks, etc.)

3) Level 3-unobservable inputs (including the Manager’s own judgments about assumptions that market participants would use in pricing the asset).

The table below categorizes amounts that are included in the Trust’s Statement of Assets and Liabilities as of June 30, 2009 based on valuation input level:

			Level 2—		Level 3—
	Level 1—		Other Significant		Significant
	Unadjusted		Observable		Unobservable
	Quoted Prices		Inputs		Inputs		Value
Assets Table Investments at Value:
Certificates of Deposit	$	—	$	209,200,023	$	—	$	209,200,023
Direct Bank Obligations		—		344,620,391		—		344,620,391
Short-Term Notes		—		788,999,029		—		788,999,029
Total Assets	$	—	$	1,342,819,443	$	—	$	1,342,819,443

Currency contracts and forwards, if any, are reported at their unrealized appreciation/depreciation at measurement date, which represents the change in the contract’s value from trade date. Futures, if any, are reported at their variation margin at measurement date, which represents the amount due to/from the Trust at that date. All additional assets and liabilities included in the above table are reported at their market value at measurement date.

See the accompanying Notes for further discussion of the methods used in determining value of the Trust’s investments, and a summary of changes to the valuation techniques, if any, during the reporting period.

See accompanying Notes to Financial Statements.

F4 | CENTENNIAL MONEY MARKET TRUST

STATEMENT OF ASSETS AND LIABILITIES June 30, 2009

Assets
Investments, at value (cost $1,342,819,443)—see accompanying statement of investments	$	1,342,819,443
Cash		138,924
Receivables and other assets:
Interest		103,643
Shares of beneficial interest sold		2,000
Other		55,141
Total assets		1,343,119,151
Liabilities
Payables and other liabilities:
Transfer and shareholder servicing agent fees		289,194
Shareholder communications		78,782
Trustees’ compensation		45,104
Legal, auditing and other professional fees		37,114
Shares of beneficial interest redeemed		4,316
Dividends		3,515
Other		5,912
Total liabilities		463,937
Net Assets	$	1,342,655,214
Composition of Net Assets
Paid-in capital	$	1,342,650,931
Accumulated net realized gain on investments		4,283
Net Assets—applicable to 1,343,110,902 shares of beneficial interest outstanding	$	1,342,655,214
Net Asset Value, Redemption Price Per Share and Offering Price Per Share	$	1.00

See accompanying Notes to Financial Statements.

F5 | CENTENNIAL MONEY MARKET TRUST

STATEMENT OF OPERATIONS For the Year Ended June 30, 2009

Investment Income
Interest	$	42,242,041
Expenses
Management fees		8,802,325
Transfer and shareholder servicing agent fees		4,344,093
Service plan fees		2,705,790
Registration and filing fees		943,008
Shareholder communications		802,546
Insurance expenses		512,244
Trustees’ compensation		93,593
Custodian fees and expenses		9,404
Other		199,447
Total expenses		18,412,450
Less waivers and reimbursements of expenses		(922,179	)
Net expenses		17,490,271
Net Investment Income		24,751,770
Net Realized Gain on Investments		154,445
Net Increase in Net Assets Resulting from Operations	$	24,906,215

See accompanying Notes to Financial Statements.

F6 | CENTENNIAL MONEY MARKET TRUST

STATEMENTS OF CHANGES IN NET ASSETS

Year Ended June 30,	2009			2008
Operations
Net investment income	$	24,751,770		$	782,617,133
Net realized gain		154,445			94,929
Net increase in net assets resulting from operations		24,906,215			782,712,062
Dividends and/or Distributions to Shareholders
Dividends from net investment income		(24,751,770	)		(782,617,133	)
Distributions from net realized gain		(228,396	)		(14,582	)
Beneficial Interest Transactions
Net decrease in net assets resulting from beneficial interest transactions		(4,095,180,634	)		(16,247,383,928	)
Net Assets
Total decrease		(4,095,254,585	)		(16,247,303,581	)
Beginning of period		5,437,909,799			21,685,213,380
End of period	$	1,342,655,214		$	5,437,909,799

See accompanying Notes to Financial Statements.

F7 | CENTENNIAL MONEY MARKET TRUST

FINANCIAL HIGHLIGHTS

Year Ended June 30,	2009			2008			2007			2006			2005
Per Share Operating Data
Net asset value, beginning of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Income from investment operations-net investment income and net realized gain1		.01			.04			.05			.04			.02
Dividends and/or distributions to shareholders:
Dividends from net investment income		(.01	)		(.04	)		(.05	)		(.04	)		(.02	)
Distributions from net realized gain		—	2		—	2		—	2		—			—
Total dividends and/or distributions to shareholders		(.01	)		(.04	)		(.05	)		(.04	)		(.02	)
Net asset value, end of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Total Return3		0.93	%		3.79	%		4.80	%		3.70	%		1.59	%
Ratios/Supplemental Data
Net assets, end of period (in millions)	$	1,343		$	5,438		$	21,685		$	22,424		$	20,307
Average net assets (in millions)	$	2,166		$	20,415		$	24,003		$	21,527		$	20,966
Ratios to average net assets:4
Net investment income		1.14	%		3.83	%		4.71	%		3.62	%		1.57	%
Total expenses		0.85	%		0.71	%		0.66	%		0.67	%		0.68	%
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		0.81	%		0.71	%		0.66	%		0.67	%		0.68	%

1.	Per share amounts calculated based on the average shares outstanding during the period.
2.	Less than $0.005 per share.
3.	Assumes an investment on the business day before the first day of the fiscal period, with all dividends and distributions reinvested in additional shares on the reinvestment date, and redemption at the net asset value calculated on the last business day of the fiscal period. Total returns are not annualized for periods less than one full year. Returns do not reflect the deduction of taxes that a shareholder would pay on trust distributions or the redemption of trust shares.
4.	Annualized for periods less than one full year.

See accompanying Notes to Financial Statements.

F8 | CENTENNIAL MONEY MARKET TRUST

NOTES TO FINANCIAL STATEMENTS

1. Significant Accounting Policies

Centennial Money Market Trust (the “Trust”) is registered under the Investment Company Act of 1940, as amended, as an open-end management investment company. The Trust’s investment objective is to seek the maximum current income that is consistent with low capital risk and the maintenance of liquidity. The Trust’s investment adviser is Centennial Asset Management Corporation (the “Manager”), a subsidiary of OppenheimerFunds, Inc. (“OFI”).

     The following is a summary of significant accounting policies consistently followed by the Trust.

Securities Valuation. The net asset value of shares of the Trust is normally determined twice each day, at Noon Eastern time and at 4:00 P.M. Eastern time on each day the New York Stock Exchange (the “Exchange”) is open for trading. Securities are valued at cost adjusted by the amortization of discount or premium to maturity (amortized cost), which approximates market value. If amortized cost is determined not to approximate market value, the fair value of the portfolio securities will be determined under procedures approved by the Trust’s Board of Trustees.

     Effective for fiscal periods beginning after November 15, 2007, FASB Statement of Financial Accounting Standards No. 157, Fair Value Measurements, establishes a hierarchy for measuring fair value of assets and liabilities. As required by the standard, each investment asset or liability of the Trust is assigned a level at measurement date based on the significance and source of the inputs to its valuation. Unadjusted quoted prices in active markets for identical securities are classified as “Level 1,” inputs other than unadjusted quoted prices for an asset that are observable are classified as “Level 2” and unobservable inputs, including the Manager’s judgment about the assumptions that a market participant would use in pricing an asset or liability are classified as “Level 3.” The inputs used for valuing securities are not necessarily an indication of the risks associated with investing in those securities. A table summarizing the Trust’s investments under these levels of classification is included following the Statement of Investments.

     “Money market-type” instruments are typically designated as Level 2.

     In the absence of a readily available unadjusted quoted market price, including for securities whose values have been materially affected by what the Manager identifies as a significant event occurring before the Trust’s assets are valued but after the close of the securities’ respective exchanges, the Manager, acting through its internal valuation committee, in good faith determines the fair valuation of that asset using consistently applied procedures under the supervision of the Board of Trustees (which reviews those fair valuations by the Manager). Those procedures include certain standardized methodologies to fair value securities. Such methodologies include, but are not limited to, pricing securities initially at cost and subsequently adjusting the value based on: changes in company specific fundamentals, changes in an appropriate securities index, or changes in the value of similar securities which may be adjusted for any discounts related to resale restrictions. When possible, such methodologies use observable market inputs such as unadjusted quoted prices

F9 | CENTENNIAL MONEY MARKET TRUST

NOTES TO FINANCIAL STATEMENTS Continued

1. Significant Accounting Policies Continued

of similar securities, observable interest rates, currency rates and yield curves. The methodologies used for valuing securities are not necessarily an indication of the risks associated with investing in those securities.

     Fair valued securities may be classified as “Level 3” if the Manager’s own assumptions about the inputs that market participants would use in valuing such securities are significant to the fair value.

     There have been no significant changes to the fair valuation methodologies during the period.

Federal Taxes. The Trust intends to comply with provisions of the Internal Revenue Code applicable to regulated investment companies and to distribute substantially all of its investment company taxable income to shareholders. Therefore, no federal income or excise tax provision is required. The Trust files income tax returns in U.S. federal and applicable state jurisdictions. The statute of limitations on the Trust’s tax return filings generally remain open for the three preceding fiscal reporting period ends.

The tax components of capital shown in the following table represent distribution requirements the Trust must satisfy under the income tax regulations, losses the Trust may be able to offset against income and gains realized in future years for federal income tax purposes.

Undistributed Net	Undistributed		Accumulated Loss
Investment Income	Long-Term Gains		Carryforward1,2
$81,375	$	—	$	—

1.	During the fiscal year ended June 30, 2009, the Trust did not utilize any capital loss carryforwards.
2.	During the fiscal year ended June 30, 2008, the Trust utilized $2,115 of capital loss carryforward to offset capital gains realized in that fiscal year.

Net investment income (loss) and net realized gain (loss) may differ for financial statement and tax purposes. The character of dividends and distributions made during the fiscal year from net investment income or net realized gains may differ from their ultimate characterization for federal income tax purposes. Also, due to timing of dividends and distributions, the fiscal year in which amounts are distributed may differ from the fiscal year in which the income or net realized gain was recorded by the Trust.

     The tax character of distributions paid during the years ended June 30, 2009 and June 30, 2008 was as follows:

	Year Ended		Year Ended
	June 30, 2009		June 30, 2008
Distributions paid from:
Ordinary income	$	24,980,037	$	782,631,715
Long-term capital gain		129		—
Total	$	24,980,166	$	782,631,715

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Trustees’ Compensation. The Board of Trustees has adopted a compensation deferral plan for independent trustees that enables trustees to elect to defer receipt of all or a portion of the annual compensation they are entitled to receive from the Trust. For purposes of determining the amount owed to the Trustee under the plan, deferred amounts are treated as though equal dollar amounts had been invested in shares of the Trust or in other Oppenheimer funds selected by the Trustee. The Trust purchases shares of the funds selected for deferral by the Trustee in amounts equal to his or her deemed investment, resulting in a Trust asset equal to the deferred compensation liability. Such assets are included as a component of “Other” within the asset section of the Statement of Assets and Liabilities. Deferral of trustees’ fees under the plan will not affect the net assets of the Trust, and will not materially affect the Trust’s assets, liabilities or net investment income per share. Amounts will be deferred until distributed in accordance to the compensation deferral plan.

Dividends and Distributions to Shareholders. Dividends and distributions to shareholders, which are determined in accordance with income tax regulations and may differ from U.S. generally accepted accounting principles, are recorded on the ex-dividend date. Income distributions, if any, are declared daily and paid monthly. Capital gain distributions, if any, are declared and paid annually but may be paid at other times to maintain the net asset value per share at $1.00.

Investment Income. Interest income is recognized on an accrual basis. Discount and premium, which are included in interest income on the Statement of Operations, are amortized or accreted daily.

Custodian Fees. “Custodian fees and expenses” in the Statement of Operations may include interest expense incurred by the Trust on any cash overdrafts of its custodian account during the period. Such cash overdrafts may result from the effects of failed trades in portfolio securities and from cash outflows resulting from unanticipated shareholder redemption activity. The Trust pays interest to its custodian on such cash overdrafts, to the extent they are not offset by positive earnings on cash balances maintained by the Trust, at a rate equal to the 1 Month LIBOR Rate plus 2.00%. The “Reduction to custodian expenses” line item, if applicable, represents earnings on cash balances maintained by the Trust during the period. Such interest expense and other custodian fees may be paid with these earnings.

Security Transactions. Security transactions are recorded on the trade date. Realized gains and losses on securities sold are determined on the basis of identified cost.

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

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NOTES TO FINANCIAL STATEMENTS Continued

1. Significant Accounting Policies Continued

Other. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of increases and decreases in net assets from operations during the reporting period. Actual results could differ from those estimates.

2. Shares of Beneficial Interest

The Trust has authorized an unlimited number of no par value shares of beneficial interest. Transactions in shares of beneficial interest were as follows:

	Year Ended June 30, 2009						Year Ended June 30, 2008
	Shares			Amount			Shares			Amount
Sold		8,729,935,379		$	8,729,935,379			53,292,947,992		$	53,292,947,992
Dividends and/or distributions reinvested		5,900,450			5,900,450			197,940,894			197,940,894
Redeemed		(12,831,016,463	)		(12,831,016,463	)		(69,738,272,814	)		(69,738,272,814	)
Net decrease		(4,095,180,634	)	$	(4,095,180,634	)		(16,247,383,928	)	$	(16,247,383,928	)

3. Fees and Other Transactions with Affiliates

Management Fees. Under the investment advisory agreement, the Trust pays the Manager a management fee based on the daily net assets of the Trust at an annual rate as shown in the following table:

Fee Schedule
Up to $250 million	0.500	%
Next $250 million	0.475
Next $250 million	0.450
Next $250 million	0.425
Next $250 million	0.400
Next $250 million	0.375
Next $500 million	0.350
Over $2 billion	0.325

Transfer Agent Fees. Shareholder Services, Inc. (“SSI”) acts as the transfer and shareholder servicing agent for the Trust. The Trust pays SSI a per account fee. For the year ended June 30, 2009, the Trust paid $12,822,227 to SSI for services to the Trust.

Service Plan (12b-1) Fees. The Trust has adopted a Service Plan (the “Plan”). It reimburses Centennial Asset Management Corporation (the “Distributor”), for a portion of its costs incurred for services provided to accounts that hold shares of the Trust.

Reimbursement is made periodically depending on asset size, at an annual rate of up to 0.20% of the average annual net assets of the Trust. The Distributor currently uses all of those fees (together with significant amounts from the Manager’s own resources) to pay dealers, brokers, banks and other financial institutions periodically for providing personal

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service and maintenance of accounts of their customers that hold shares of the Trust. Fees incurred by the Trust under the Plan are detailed in the Statement of Operations. Effective January 31, 2009, the Board of Trustees of the Trust has set the rate for the fees of the Plan at zero.

Waivers and Reimbursements of Expenses. Effective January 1, 2009, the Manager has voluntarily undertaken to waive fees to the extent necessary to assist the Trust in attempting to maintain a positive yield. During the year ended June 30, 2009, the Manager waived fees and/or reimbursed the Trust $922,179. There is no guarantee that the Trust will maintain a positive yield. This undertaking may be amended or withdrawn at any time.

     SSI has voluntarily agreed to limit transfer and shareholder servicing agent fees to 0.35% of average annual net assets of the Trust. This undertaking may also be amended or withdrawn at any time.

4. Illiquid Securities

As of June 30, 2009, investments in securities included issues that are illiquid. Investments may be illiquid because they do not have an active trading market, making it difficult to value them or dispose of them promptly at an acceptable price. The Trust will not invest more than 10% of its net assets (determined at the time of purchase and reviewed periodically) in illiquid securities. Securities that are illiquid are marked with an applicable footnote on the Statement of Investments.

5. Temporary Guarantee Program for Money Market Funds

The Board of Trustees elected for the Trust to participate in the Temporary Guarantee Program for Money Market Funds (the “Program”) established by the U.S. Treasury Department. The Treasury Department accepted the Trust’s application to participate in the Program and entered into a Guarantee Agreement with the Trust dated as of September 19, 2008. The Trust also notified the Treasury Department of its intent to continue its participation in the Program through April 30, 2009. The Program cannot be extended beyond September 18, 2009.

     Under the Program, shareholders of the Trust as of the close of business on September 19, 2008 may be guaranteed against loss in the event that the Trust’s net asset value falls below $0.995. The Program applies only to shareholders of record as of the close of business on September 19, 2008. The number of shares covered by the Program will be the lesser of (a) the number of shares of the Trust owned by the shareholder on September 19, 2008 or (b) the number of shares owned by the shareholder on the date the Trust’s net asset value falls below $0.995. If the number of shares of the Trust a shareholder holds after September 19, 2008 fluctuates during the Program period due to purchases or redemptions of shares, any shares in excess of the amount held as of the close of business on September 19, 2008 will not be covered.

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NOTES TO FINANCIAL STATEMENTS Continued

5. Temporary Guarantee Program for Money Market Funds Continued

The Trust paid a fee to participate in the Program’s initial term in the amount equal to 0.01% of the Trust’s net assets as of the close of business on September 19, 2008. The Trust paid a fee to continue its participation in the Program through April 30, 2009 in the amount of 0.015% of the Trust’s net assets as of the close of business on September 19, 2008. Participation in any further extension of the Program would require payment of an additional fee. Fees paid by the Trust to participate in the Program are shown as “Insurance expense” on the Statement of Operations.

6. Subsequent Events Evaluation

The Trust has evaluated the need for disclosures and/or adjustments resulting from subsequent events through August 17, 2009, the date the financial statements were available to be issued. This evaluation determined that there were no subsequent events that necessitated disclosures and/or adjustments.

7. Pending Litigation

During 2009, a number of complaints have been filed in federal courts against OFI — the Manager’s immediate parent, the Sub-Distributor — OppenheimerFunds Distributor, Inc., and other mutual funds (“Defendant Funds”) advised by OFI and distributed by the Sub-Distributor — excluding the Trust. The complaints naming the Defendant Funds also name certain officers, trustees and former trustees of the respective Defendant Funds. The plaintiffs seek class action status on behalf of purchasers of shares of the respective Defendant Fund during a particular time period. The complaints against the Defendant Funds raise claims under federal securities laws alleging that, among other things, the disclosure documents of the respective Defendant Fund contained misrepresentations and omissions, that such Defendant Fund’s investment policies were not followed, and that such Defendant Fund and the other defendants violated federal securities laws and regulations. The plaintiffs seek unspecified damages, equitable relief and an award of attorneys’ fees and litigation expenses.

     A complaint has been brought in state court against OFI, the Sub-Distributor and another subsidiary of OFI (but not against the Trust), on behalf of the Oregon College Savings Plan Trust. The complaint alleges breach of contract, breach of fiduciary duty, negligence and violation of state securities laws, and seeks compensatory damages, equitable relief and an award of attorneys’ fees and litigation expenses.

     Other complaints have been filed in 2008 and 2009 in state and federal courts, by investors who made investments through an affiliate of OFI, against OFI and certain of its affiliates. Those complaints relate to the alleged investment fraud perpetrated by Bernard Madoff and his firm (“Madoff”) and allege a variety of claims, including breach of fiduciary duty, fraud, negligent misrepresentation, unjust enrichment, and violation of federal and state securities laws and regulations, among others. They seek unspecified damages, equitable relief and an award of attorneys’ fees and litigation expenses. None of the suits have

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named the Manager, the Distributor, the Sub-Distributor, any of the Oppenheimer mutual funds or any of their independent Trustees or Directors. None of the Oppenheimer or Centennial funds invested in any funds or accounts managed by Madoff.

     OFI believes that the lawsuits described above are without legal merit and intends to defend them vigorously. The Defendant Funds’ Boards of Trustees have also engaged counsel to defend the suits vigorously on behalf of those Funds, their boards and the Trustees named in those suits. While it is premature to render any opinion as to the likelihood of an outcome in these lawsuits, or whether any costs that the Defendant Funds may bear in defending the suits might not be reimbursed by insurance, OFI believes that these suits should not impair the ability of the Manager or the Sub-Distributor to perform their respective duties to the Trust, and that the outcome of all of the suits together should not have any material effect on the operations of any of the Oppenheimer or Centennial funds.

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Trustees and Shareholders of Centennial Money Market Trust:

We have audited the accompanying statement of assets and liabilities of Centennial Money Market Trust, including the statement of investments, as of June 30, 2009, and the related statements of operations and changes in net assets and the financial highlights for the year then ended. These financial statements and financial highlights are the responsibility of the Trust’s management. Our responsibility is to express an opinion on these financial statements and financial highlights based on our audit. The accompanying financial statements and financial highlights of Centennial Money Market Trust for the years ended prior to July 1, 2008 were audited by other auditors whose report dated August 8, 2008 expressed an unqualified opinion on those statements and financial highlights.

     We conducted our audit 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 and financial highlights are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. Our procedures included confirmation of securities owned as of June 30, 2009, by correspondence with the custodian. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audit provides a reasonable basis for our opinion.

     In our opinion, the financial statements and financial highlights referred to above present fairly, in all material respects, the financial position of Centennial Money Market Trust as of June 30, 2009, and the results of its operations, the changes in its net assets and the financial highlights for the year then ended, in conformity with U.S. generally accepted accounting principles.

KPMG llp

Denver, Colorado
August 17, 2009

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FEDERAL INCOME TAX INFORMATION Unaudited

In early 2009, if applicable, shareholders of record received information regarding all dividends and distributions paid to them by the Trust during calendar year 2008. Regulations of the U.S. Treasury Department require the Trust to report this information to the Internal Revenue Service.

     Recent tax legislation allows a regulated investment company to designate distributions not designated as capital gain distributions, as either interest related dividends or short-term capital gain dividends, both of which are exempt from the U.S. withholding tax applicable to non U.S. taxpayers. For the fiscal year ended June 30, 2009, $24,721,097 or 99.88% of the ordinary distributions paid by the Trust qualifies as an interest related dividend and $154,445 or 67.66% of the short-term capital gain distribution paid and to be paid by the Trust qualifies as a short-term capital gain dividend.

     The foregoing information is presented to assist shareholders in reporting distributions received from the Trust to the Internal Revenue Service. Because of the complexity of the federal regulations which may affect your individual tax return and the many variations in state and local tax regulations, we recommend that you consult your tax advisor for specific guidance.

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PORTFOLIO PROXY VOTING POLICIES AND PROCEDURES; UPDATES TO STATEMENTS OF INVESTMENTS Unaudited

The Trust has adopted Portfolio Proxy Voting Policies and Procedures under which the Trust votes proxies relating to securities (“portfolio proxies”) held by the Trust. A description of the Trust’s Portfolio Proxy Voting Policies and Procedures is available (i) without charge, upon request, by calling the Trust toll-free at 1.800.525.7048, (ii) on the Trust’s website at www.oppenheimerfunds.com, and (iii) on the SEC’s website at www.sec.gov. In addition, the Trust is required to file Form N-PX, with its complete proxy voting record for the 12 months ended June 30th, no later than August 31st of each year. The Trust’s voting record is available (i) without charge, upon request, by calling the Trust toll-free at 1.800.525.7048, and (ii) in the Form N-PX filing on the SEC’s website at www.sec.gov.

     The Trust files its complete schedule of portfolio holdings with the SEC for the first quarter and the third quarter of each fiscal year on Form N-Q. The Trusts Form N-Q filings are available on the SEC’s website at http://www.sec.gov. Those forms may be reviewed and copied at the SEC’s Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330.

Householding — Delivery of Shareholder Documents

     This is to inform you about OppenheimerFunds’ “householding” policy. If more than one member of your household maintains an account in a particular fund, OppenheimerFunds will mail only one copy of the fund’s prospectus, annual and semiannual report and privacy policy. The consolidation of these mailings, called householding, benefits your fund through reduced mailing expense, and benefits you by reducing the volume of mail you receive from OppenheimerFunds. Householding does not affect the delivery of your account statements.

     Please note that we will continue to household these mailings for as long as you remain an OppenheimerFunds shareholder, unless you request otherwise. If you prefer to receive multiple copies of these materials, please call us at 1.800.CALL-OPP (225-5677). You may also notify us in writing or via email. We will begin sending you individual copies of the prospectus, reports and privacy policy within 30 days of receiving your request to stop householding.

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TRUSTEES AND OFFICERS Unaudited

Name, Position(s) Held with the	Principal Occupation(s) During the Past 5 Years; Other Trusteeships/Directorships
Trust, Length of Service, Age	Held; Number of Portfolios in the Trust Complex Currently Overseen
INDEPENDENT TRUSTEES	The address of each Trustee in the chart below is 6803 S. Tucson Way, Centennial, Colorado 80112-3924. Each Trustee serves for an indefinite term, or until his or her resignation, retirement, death or removal.
William L. Armstrong, Chairman of the Board of Trustees (since 2003), Trustee (since 2000) Age: 72	President, Colorado Christian University (since 2006); Chairman, Cherry Creek Mortgage Company (since 1991), Chairman, Centennial State Mortgage Company (since 1994), Chairman, The El Paso Mortgage Company (since 1993); Chairman, Ambassador Media Corporation (since 1984); Chairman, Broadway Ventures (since 1984); Director of Helmerich & Payne, Inc. (oil and gas drilling/production company) (since 1992), former Director of Campus Crusade for Christ (non-profit) (1991-2008); former Director, The Lynde and Harry Bradley Foundation, Inc. (non-profit organization) (2002-2006); former Chairman of: Transland Financial Services, Inc. (private mortgage banking company) (1997-2003), Great Frontier Insurance (1995-2000), Frontier Real Estate, Inc. (residential real estate brokerage) (1994-2000) and Frontier Title (title insurance agency) (1995-2000); former Director of the following: UNUMProvident (insurance company) (1991-2004), Storage Technology Corporation (computer equipment company) (1991-2003) and International Family Entertainment (television channel) (1992-1997); U.S. Senator (January 1979-January 1991). Oversees 38 portfolios in the OppenheimerFunds complex.
George C. Bowen, Trustee (since 1998) Age: 72	Assistant Secretary and Director of the Manager (December 1991-April 1999); President, Treasurer and Director of Centennial Capital Corporation (June 1989-April 1999); Chief Executive Officer and Director of MultiSource Services, Inc. (March 1996-April 1999); Mr. Bowen held several positions with OppenheimerFunds, Inc. and with subsidiary or affiliated companies of OppenheimerFunds, Inc. (September 1987-April 1999). Oversees 38 portfolios in the OppenheimerFunds complex.
Edward L. Cameron, Trustee (since 2000) Age: 70	Member of The Life Guard of Mount Vernon (George Washington historical site) (June 2000-June 2006); Partner of PricewaterhouseCoopers LLP (accounting firm) (July 1974-June 1999); Chairman of Price Waterhouse LLP Global Investment Management Industry Services Group (accounting firm) (July 1994-June 1998). Oversees 38 portfolios in the OppenheimerFunds complex.
Jon S. Fossel, Trustee (since 1990) Age: 67	Chairman of the Board (since 2006) and Director (since June 2002) of UNUMProvident (insurance company); Director of Northwestern Energy Corp. (public utility corporation) (since November 2004); Director of P.R. Pharmaceuticals (October 1999-October 2003); Director of Rocky Mountain Elk Foundation (non-profit organization) (February 1998-February 2003 and February 2005-February 2007); Chairman and Director (until October 1996) and President and Chief Executive Officer (until October 1995) of OppenheimerFunds, Inc.; President, Chief Executive Officer and Director of the following: Oppenheimer Acquisition Corp. (“OAC”) (parent holding company of OppenheimerFunds, Inc.), Shareholders Services, Inc. and Shareholder Financial Services, Inc. (until October 1995). Oversees 38 portfolios in the OppenheimerFunds complex.
Sam Freedman, Trustee (since 1996) Age: 68	Director of Colorado UpLIFT (charitable organization) (since September 1984). Mr. Freedman held several positions with OppenheimerFunds, Inc. and with subsidiary or affiliated companies of OppenheimerFunds, Inc. (until October 1994). Oversees 38 portfolios in the OppenheimerFunds complex.

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TRUSTEES AND OFFICERS Unaudited / Continued

Name, Position(s) Held with the	Principal Occupation(s) During the Past 5 Years; Other Trusteeships/Directorships
Trust, Length of Service, Age	Held; Number of Portfolios in the Trust Complex Currently Overseen
Richard F. Grabish, Trustee (since 2001) Age: 60	Formerly Senior Vice President and Assistant Director of Sales and Marketing (March 1997-December 2007), Director (March 1987-December 2007) and Manager of Private Client Services (June 1985-June 2005) of A.G. Edwards & Sons, Inc. (broker/dealer and investment firm); Chairman and Chief Executive Officer of A.G. Edwards Trust Company, FSB (March 2001-December 2007); President and Vice Chairman of A.G. Edwards Trust Company, FSB (investment adviser) (April 1987-March 2001); President of A.G. Edwards Trust Company, FSB (investment adviser) (June 2005-December 2007). Oversees 16 portfolios in the OppenheimerFunds complex.
Beverly L. Hamilton, Trustee (since 2002) Age: 62	Trustee of Monterey Institute for International Studies (educational organization) (since February 2000); Board Member of Middlebury College (educational organization) (since December 2005); Director of The California Endowment (philanthropic organization) (April 2002-April 2008); Director (February 2002-2005) and Chairman of Trustees (2006-2007) of the Community Hospital of Monterey Peninsula; Director (October 1991-2005) and Vice Chairman (since 2006) of American Funds’ Emerging Markets Growth Fund, Inc. (mutual fund); President of ARCO Investment Management Company (February 1991-April 2000); Member of the investment committees of The Rockefeller Foundation (2001-2006) and The University of Michigan (since 2000); Advisor at Credit Suisse First Boston’s Sprout venture capital unit (venture capital fund) (1994-January 2005); Trustee of MassMutual Institutional Funds (investment company) (1996-June 2004); Trustee of MML Series Investment Fund (investment company) (April 1989-June 2004); Member of the investment committee of Hartford Hospital (2000-2003); and Advisor to Unilever (Holland) pension fund (2000-2003). Oversees 38 portfolios in the OppenheimerFunds complex.
Robert J. Malone, Trustee (since 2002) Age: 64	Board of Directors of Opera Colorado Foundation (non-profit organization) (since March 2008); Director of Jones Knowledge, Inc. (since 2006); Director of Jones International University (educational organization) (since August 2005); Chairman, Chief Executive Officer and Director of Steele Street Bank & Trust (commercial banking) (since August 2003); Director of Colorado UpLIFT (charitable organization) (since 1986); Trustee of the Gallagher Family Foundation (non-profit organization) (since 2000); Former Chairman of U.S. Bank-Colorado (subsidiary of U.S. Bancorp and formerly Colorado National Bank) (July 1996-April 1999); Director of Commercial Assets, Inc. (real estate investment trust) (1993-2000); Director of Jones Knowledge, Inc. (2001-July 2004); and Director of U.S. Exploration, Inc. (oil and gas exploration) (1997-February 2004). Oversees 38 portfolios in the OppenheimerFunds complex.
F. William Marshall, Jr., Trustee (since 2000) Age: 67	Trustee Emeritas of Worcester Polytech Institute (WPI) (private university) (since 2009); Trustee of MassMutual Select Funds (formerly MassMutual Institutional Funds) (investment company) (since 1996) and MML Series Investment Fund (investment company) (since 1996); President and Treasurer of the SIS Funds (private charitable fund) (since January 1999); Former Trustee of WPI (1985-2008); Former Chairman of the Board (2004-2006) and Former Chairman of the Investment Committee of WPI (1994-2008); Chairman of SIS & Family Bank, F.S.B. (formerly SIS Bank) (commercial bank) (January 1999-July 1999); Executive Vice President of Peoples Heritage Financial Group, Inc. (commercial bank) (January 1999-July 1999); and Former President and Chief Executive Officer of SIS Bancorp. (1993-1999). Oversees 40 portfolios in the OppenheimerFunds complex.

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Name, Position(s) Held with the	Principal Occupation(s) During the Past 5 Years; Other Trusteeships/Directorships
Trust, Length of Service, Age	Held; Number of Portfolios in the Trust Complex Currently Overseen
INTERESTED TRUSTEE AND OFFICER	The address of Mr. Murphy is Two World Financial Center, 225 Liberty Street, 11th Floor, New York, New York 10281-1008. Mr. Murphy serves as a Trustee for an indefinite term, or until his resignation, retirement, death or removal and as an Officer for an indefinite term, or until his resignation, retirement, death or removal. Mr. Murphy is an interested Trustee due to his positions with OppenheimerFunds, Inc. and its affiliates.

John V. Murphy, Trustee, President and Principal Executive Officer (since 2001) Age: 59	Chairman and Director of OppenheimerFunds, Inc. (since June 2001); Chief Executive Officer of OppenheimerFunds, Inc. (June 2001-December 2008); President of OppenheimerFunds, Inc. (September 2000-February 2007); President and director or trustee of other Oppenheimer funds; President and Director of Oppenheimer Acquisition Corp. (“OAC”) (the Manager’s parent holding company) and of Oppenheimer Partnership Holdings, Inc. (holding company subsidiary of OppenheimerFunds, Inc.) (since July 2001); Director of OppenheimerFunds Distributor, Inc. (subsidiary of OppenheimerFunds, Inc.) November 2001-December 2006); Chairman and Director of Shareholder Services, Inc. and of Shareholder Financial Services, Inc. (transfer agent subsidiaries of OppenheimerFunds, Inc.) (since July 2001); President and Director of OppenheimerFunds Legacy Program (charitable trust program established by OppenheimerFunds, Inc.) (since July 2001); Director of the following investment advisory subsidiaries of OppenheimerFunds, Inc.: the Manager, OFI Institutional Asset Management, Inc. and Trinity Investment Management Corporation (since November 2001), HarbourView Asset Management Corporation and OFI Private Investments, Inc. (since July 2001); President (since November 2001) and Director (since July 2001) of Oppenheimer Real Asset Management, Inc.; Executive Vice President of Massachusetts Mutual Life Insurance Company (OAC’s parent company) (since February 1997); Director of DLB Acquisition Corporation (holding company parent of Babson Capital Management LLC) (since June 1995); Chairman (since October 2007) and Member of the Investment Company Institute’s Board of Governors (since October 2003). Oversees 102 portfolios in the OppenheimerFunds complex.
OTHER OFFICERS OF THE TRUST	The addresses of the Officers in the chart below are as follows: for Mr. Zack, Two World Financial Center, 225 Liberty Street, New York, New York 10281-1008, for Messrs. Vandehey, Wixted and Ms. Wolf, 6803 S. Tucson Way, Centennial, Colorado 80112-3924. Each Officer serves for an indefinite tern or until his or her resignation, retirement, death or removal.
Carol E. Wolf, Vice President and Portfolio Manager (since 1987) Age: 57	Senior Vice President of OppenheimerFunds, Inc. (since June 2000) and of HarbourView Asset Management Corporation (since June 2003). A portfolio manager and officer of 7 portfolios in the OppenheimerFunds complex.
Mark S. Vandehey, Vice President and Chief Compliance Officer (since 2004) Age: 58	Senior Vice President and Chief Compliance Officer of OppenheimerFunds, Inc. (since March 2004); Chief Compliance Officer of OppenheimerFunds Distributor, Inc., and Shareholder Services, Inc. (since March 2004); Vice President of the Manager, OppenheimerFunds Distributor, Inc., and Shareholder Services, Inc. (since June 1983); Former Vice President and Director of Internal Audit of OppenheimerFunds, Inc. (1997-February 2004). An officer of 102 portfolios in the Oppenheimer funds complex.
Brian W. Wixted, Treasurer and Principal Financial & Accounting Officer (since 1999) Age: 49	Senior Vice President of OppenheimerFunds, Inc. (since March 1999); Treasurer of the Manager and the following: Shareholder Services, Inc., HarbourView Asset Management Corporation, Shareholder Financial Services, Inc., Oppenheimer Real Asset Management, Inc. and Oppenheimer Partnership Holdings, Inc. (March 1999-June 2008), OFI Private Investments, Inc. (March 2000-June 2008),

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TRUSTEES AND OFFICERS Unaudited / Continued

Name, Position(s) Held with the	Principal Occupation(s) During the Past 5 Years; Other Trusteeships/Directorships
Trust, Length of Service, Age	Held; Number of Portfolios in the Trust Complex Currently Overseen
Brian W. Wixted, Continued	OppenheimerFunds International Ltd. and OppenheimerFunds plc (since May 2000), OFI Institutional Asset Management, Inc. (since November 2000), and OppenheimerFunds Legacy Program (charitable trust program established by the Manager) (since June 2003); Treasurer and Chief Financial Officer of OFI Trust Company (trust company subsidiary of OppenheimerFunds, Inc.) (since May 2000); Assistant Treasurer of OAC (March 1999-June 2008); and Assistant Treasurer of the Manager and Distributor (March 1999-October 2003) and OppenheimerFunds Legacy Program (April 2000-June 2003). An officer of 102 portfolios in the OppenheimerFunds complex.
Robert G. Zack, Vice President and Secretary (since 2001) Age: 60	Executive Vice President (since January 2004) and General Counsel (since March 2002) of OppenheimerFunds, Inc.; General Counsel of the Manager and Distributor (since December 2001); General Counsel and Director of OppenheimerFunds Distributor, Inc. (since December 2001); Senior Vice President, General Counsel and Director of the Transfer Agent, Shareholder Financial Services, Inc., OFI Private Investments, Inc. and OFI Trust Company (since November 2001); Senior Vice President and General Counsel of HarbourView Asset Management Corporation (since December 2001); Secretary and General Counsel of OAC (since November 2001); Assistant Secretary (since September 1997) and Director (since November 2001) of OppenheimerFunds International Ltd. and OppenheimerFunds plc; Vice President and Director of Oppenheimer Partnership Holdings, Inc. (since December 2002); Director of Oppenheimer Real Asset Management, Inc. (since November 2001); Vice President of OppenheimerFunds Legacy Program (since June 2003); Senior Vice President and General Counsel of OFI Institutional Asset Management, Inc. (since November 2001); Director of OppenheimerFunds International Distributor Limited (since December 2003); Senior Vice President (May 1985- December 2003). An officer of 102 portfolios in the OppenheimerFunds complex.

The Trust’s Statement of Additional Information contains additional information about the Trust’s Trustees and Officers and is available without charge upon request.

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CENTENNIAL MONEY MARKET TRUST

Manager and Distributor	Centennial Asset Management Corporation
Sub-Distributor	Oppenheimer Funds Distributor, Inc.
Transfer and Shareholder Servicing Agent	Shareholder Services, Inc.
Independent Registered Public Accounting Firm	KPMG llp
Counsel	K&L Gates LLP
	For more complete information about Centennial Money Market Trust, please refer to the Prospectus. To obtain a copy, call your financial advisor, or contact Shareholder Services, Inc. at 1.800.525.9310. Please read the prospectus carefully before you invest any money.

©Copyright 2009 OppenheimerFunds, Inc. All rights reserved.

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PRIVACY POLICY NOTICE

As a Centennial fund shareholder, you are entitled to know how we protect your personal information, and how we limit its disclosure.

Information sources. We obtain nonpublic information about our shareholders from the following sources;

• Application or other forms

• Your transactions with us, our affiliates, or others

• A software program, often referred to as a “cookie,” which indicates which parts of a website you’ve visited

Protection of information. We do not disclose any nonpublic personal information (such as names on a customer list) about current or former customers to anyone, except as permitted by law.

Disclosure of information. We send your financial advisor (as designated by you) copies of confirmations, quarterly account statements and other documents reporting activity in your fund accounts. We may also use details about you and your investments to help us, our financial service affiliates, or firms that jointly market their financial products and services with ours, to better serve your investment needs or suggest financial services or educational material that may be of interest to you. If this requires us to provide you with an opportunity to “opt in” or “opt out” of such information sharing with a firm not affiliated with us, you will receive notification on how to do so, before any sharing takes place.

Right of refusal. We will not disclose your personal information to unaffiliated third parties (except as permitted by law), unless we first offer you a reasonable opportunity to refuse or “opt out” of such disclosure.

Emails. As a security measure, we do not include personal or account information in nonsecure emails, and we advise you not to send such information to us in nonsecure emails.

Other security measures. We maintain physical, electronic and procedural safeguards to protect your personal account information. Our employees and agents have access to that information only so that they may offer products or provide services to you, for example, when responding to your account questions.

This joint notice describes the privacy policies of the Centennial funds, Centennial Asset Management Corporation, the trustee of Centennial Individual Retirement Accounts (IRAs) and the custodian of the Centennial 403(b)(7) tax-sheltered custodial accounts. It applies to all Centennial fund accounts you presently have, or may open in the future, using your Social Security number—whether or not you remain a shareholder of our funds. This notice was last updated April 14, 2004. In the event that it is updated or changed, we will mail you the updated notice. If you have any questions about these privacy policies, write to us at P.O. Box 5143, Denver, CO 80217-5143 or call us at 1.800.525.9310.

15 | CENTENNIAL MONEY MARKET TRUST

RA0150.001.0609 August 21, 2009 Printed on recycled paper

Item 2. Code of Ethics.

The registrant has adopted a code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller or persons performing similar functions.

Item 3. Audit Committee Financial Expert.

The Board of Trustees of the registrant has determined that George C. Bowen, the Chairman of the Board’s Audit Committee, is the audit committee financial expert and that Mr. Bowen is “independent” for purposes of this Item 3.

Item 4. Principal Accountant Fees and Services.

(a) Audit Fees

The principal accountant for the audit of the registrant’s annual financial statements was KPMG LLP for 2009 and Deloitte and Touche LLP for 2008. KPMG billed $23,700 in fiscal 2009 and Deloitte and Touche billed $36,625 in fiscal 2008.

(b) Audit-Related Fees

The principal accountant for the audit of the registrant’s annual financial statements billed no such fees during the last two fiscal years.

The principal accountant for the audit of the registrant’s annual financial statements billed $271,540 in fiscal 2009 and $317,936 in fiscal 2008 to the registrant’s investment adviser or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant.

Such services include: internal control reviews.

(c) Tax Fees

The principal accountant for the audit of the registrant’s annual financial statements billed $4,100 in fiscal 2009 and no such fees in fiscal 2008.

The principal accountant for the audit of the registrant’s annual financial statements billed no such fees during the last two fiscal years to the registrant’s investment adviser or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant.

Such services include: tax filings.

(d) All Other Fees

The principal accountant for the audit of the registrant’s annual financial statements billed no such fees during the last two fiscal years.

The principal accountant for the audit of the registrant’s annual financial statements billed no such fees during the last two fiscal years to the registrant’s investment adviser or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant.

(e)	(1) During its regularly scheduled periodic meetings, the registrant’s audit committee will pre-approve all audit, audit-related, tax and other services to be provided by the principal accountants of the registrant.
	The audit committee has delegated pre-approval authority to its Chairman for any subsequent new engagements that arise between regularly scheduled meeting dates provided that any fees such pre-approved are presented to the audit committee at its next regularly scheduled meeting.
	Under applicable laws, pre-approval of non-audit services maybe waived provided that: 1) the aggregate amount of all such services provided constitutes no more than five percent of the total amount of fees paid by the registrant to it principal accountant during the fiscal year in which services are provided 2) such services were not recognized by the registrant at the time of engagement as non-audit services and 3) such services are promptly brought to the attention of the audit committee of the registrant and approved prior to the completion of the audit.
	(2) 100%
(f)	Not applicable as less than 50%.
(g)	The principal accountant for the audit of the registrant’s annual financial statements billed $275,640 in fiscal 2009 and $317,936 in fiscal 2008 to the registrant and the registrant’s investment adviser or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant related to non-audit fees. Those billings did not include any prohibited non-audit services as defined by the Securities Exchange Act of 1934.
(h)	The registrant’s audit committee of the board of trustees has considered whether the provision of non-audit services that were rendered to the registrant’s investment adviser, and any entity controlling, controlled by, or under common control with the investment adviser that provides ongoing services to the registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant’s independence. No such services were rendered.

Item 5. Audit Committee of Listed Registrants

Not applicable.

Item 6. Schedule of 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. Purchases 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.

The Fund’s Governance Committee Provisions with Respect to Nominations of Directors/Trustees to the Respective Boards

1.

The Fund’s Governance Committee (the “Committee”) will evaluate potential Board candidates to assess their qualifications. The Committee shall have the authority, upon approval of the Board, to retain an executive search firm to assist in this effort. The Committee may consider recommendations by business and personal contacts of current Board members and by executive search firms which the Committee may engage from time to time and may also consider shareholder recommendations. The Committee may consider the advice and recommendation of the Funds’ investment manager and its affiliates in making the selection.

2.

The Committee shall screen candidates for Board membership. The Committee has not established specific qualifications that it believes must be met by a trustee nominee. In evaluating trustee nominees, the Committee considers, among other things, an individual’s background, skills, and experience; whether the individual is an “interested person” as defined in the Investment Company Act of 1940; and whether the individual would be deemed an “audit committee financial expert” within the meaning of applicable SEC rules. The Committee also considers whether the individual’s background, skills, and experience will complement the background, skills, and experience of other nominees and will contribute to the Board. There are no differences in the manner in which the Committee evaluates nominees for trustees based on whether the nominee is recommended by a shareholder.

3. The Committee may consider nominations from shareholders for the Board at such times as the Committee meets to consider new nominees for the Board. The Committee shall have the sole discretion to determine the candidates to present to the Board and, in such cases where required, to shareholders. Recommendations for trustee nominees should, at a minimum, be accompanied by the following:

• the name, address, and business, educational, and/or other pertinent background of the person being recommended;

• a statement concerning whether the person is an “interested person” as defined in the Investment Company Act of 1940;

• any other information that the Funds would be required to include in a proxy statement concerning the person if he or she was nominated; and

• the name and address of the person submitting the recommendation and, if that person is a shareholder, the period for which that person held Fund shares.

The recommendation also can include any additional information which the person submitting it believes would assist the Committee in evaluating the recommendation.

4.

Shareholders should note that a person who owns securities issued by Massachusetts Mutual Life Insurance Company (the parent company of the Funds’ investment adviser) would be deemed an “interested person” under the Investment Company Act of 1940. In addition, certain other relationships with Massachusetts Mutual Life Insurance Company or its subsidiaries, with registered broker-dealers, or with the Funds’ outside legal counsel may cause a person to be deemed an “interested person.”

5.

Before the Committee decides to nominate an individual as a trustee, Committee members and other directors customarily interview the individual in person. In addition, the individual customarily is asked to complete a detailed questionnaire which is designed to elicit information which must be disclosed under SEC and stock exchange rules and to determine whether the individual is subject to any statutory disqualification from serving as a trustee of a registered investment company.

Item 11. Controls and Procedures.

Based on their evaluation of the registrant’s disclosure controls and procedures (as defined in rule 30a-3(c) under the Investment Company Act of 1940 (17 CFR 270.30a-3(c)) as of 06/30/2009, the registrant’s principal executive officer and principal financial officer found the registrant’s disclosure controls and procedures to provide reasonable assurances that information required to be disclosed by the registrant in the reports that it files under the Securities Exchange Act of 1934 (a) is accumulated and communicated to registrant’s management, including its principal executive officer and principal financial officer, to allow timely decisions regarding required disclosure, and (b) is recorded,

processed, summarized and reported, within the time periods specified in the rules and forms adopted by the U.S. Securities and Exchange Commission.

There have been no changes in the registrant’s internal controls over financial reporting that occurred during the registrant’s second fiscal quarter of the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Exhibits.

(a)	(1) Exhibit attached hereto.
	(2) Exhibits attached hereto.
	(3) Not applicable.
(b)	Exhibit attached hereto.

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.

Centennial Money Market Trust

By:	/s/ John V. Murphy
	John V. Murphy
	Principal Executive Officer
Date: 08/11/2009

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 V. Murphy
	John V. Murphy
	Principal Executive Officer
Date: 08/11/2009

By:	/s/ Brian W. Wixted
	Brian W. Wixted
	Principal Financial Officer
Date: 08/11/2009

EX-99.CODE ETH

EX-99.CODE ETH

CODE OF ETHICS
FOR PRINCIPAL EXECUTIVE AND SENIOR FINANCIAL OFFICERS

OF THE OPPENHEIMER FUNDS

AND OF OPPENHEIMERFUNDS, INC.

          This Code of Ethics for Principal Executive and Senior Financial Officers (referred to in this document as the “Code”) has been adopted by each of the investment companies for which OppenheimerFunds, Inc. or one of its subsidiaries or affiliates (referred to collectively in this document as “OFI”) acts as investment adviser (individually, a “Fund” and collectively, the “Funds”), and by OFI to effectuate compliance with Section 406 under the Sarbanes-Oxley Act of 2002 and the rules adopted to implement Section 406.

          This Code applies to OFI’s and each Fund’s principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions (“Covered Officers”). A listing of positions currently within the ambit of Covered Officers is attached as Exhibit A.¹

1. Purpose of the Code

          This Code sets forth standards and procedures that are reasonably designed to deter wrongdoing and promote:

• honest and ethical conduct, including the ethical handling of actual or apparent conflicts of interest between personal and professional relationships;

• full, fair, accurate, timely, and understandable disclosure in reports and documents that a Fund files with, or submits to, the U.S. Securities and Exchange Commission (“SEC”) and in other public communications made by the Fund;

• compliance with applicable governmental laws, rules and regulations;

• the prompt internal reporting of violations of this Code to the Code Administrator identified below; and

• accountability for adherence to this Code.

¹ The obligations imposed by this Code on Covered Officers are separate from and in addition to any obligations that may be imposed on such persons as Covered Persons under the Code of Ethics adopted by OFI and the Funds under Rule 17j-1 of the Investment Company Act of 1940, as amended and any other code of conduct applicable to Covered Officers in whatever capacity they serve. This Code does not incorporate by reference any provisions of the Rule 17j-1 Code of Ethics and accordingly, any violations or waivers granted under the Rule 17j-1 Code of Ethics will not be considered a violation or waiver under this Code.

          In general, the principles that govern honest and ethical conduct, including the avoidance of conflicts of interest between personal and professional relationships, reflect, at the minimum, the following: (1) the duty at all times in performing any responsibilities as a Fund financial officer, controller, accountant or principal executive officer to place the interests of the Funds ahead of personal interests; (2) the fundamental standard that Covered Officers should not take inappropriate advantage of their positions; (3) the duty to assure that a Fund’s financial statements and reports to its shareholders are prepared honestly and accurately in accordance with applicable rules, regulations and accounting standards; and (4) the duty to conduct the Funds’ business and affairs in an honest and ethical manner. Each Covered Officer should be sensitive to situations that may give rise to actual as well as apparent conflicts of interest.

          It is acknowledged that, as a result of the contractual relationship between each Fund and OFI, of which the Covered Officers are also officers or employees, and subject to OFI’s fiduciary duties to each Fund, the Covered Officers will, in the normal course of their duties, be involved in establishing policies and implementing decisions that will have different effects on OFI and the Funds. It is further acknowledged that the participation of the Covered Officers in such activities is inherent in the contractual relationship between each Fund and OFI and is consistent with the expectations of the Board of Trustees/Directors of the performance by the Covered Officers of their duties as officers of the Funds.

2. Prohibitions

          The specific provisions and reporting requirements of this Code are concerned primarily with promoting honest and ethical conduct and avoiding conflicts of interest in personal and professional relationships. No Covered Officer may use information concerning the business and affairs of a Fund, including the investment intentions of a Fund, or use his or her ability to influence such investment intentions, for personal gain to himself or herself, his or her family or friends or any other person or in a manner detrimental to the interests of a Fund or its shareholders.

          No Covered Officer may use his or her personal influence or personal relationships to influence the preparation and issuance of financial reports of a Fund whereby the Covered Officer would benefit personally to the detriment of the Fund and its shareholders.

          No Covered Officer shall intentionally for any reason take any action or fail to take any action in connection with his or her official acts on behalf of a Fund that causes the Fund to violate applicable laws, rules and regulations.

          No Covered Officer shall, in connection with carrying out his or her official duties and responsibilities on behalf of a Fund:

(i)	employ any device, scheme or artifice to defraud a Fund or its shareholders;
(ii)	intentionally cause a Fund to make any untrue statement of a material fact or omit to state a material fact necessary in order to

	make the statements made, in light of the circumstances under which they are made, not misleading in its official documents, regulatory filings, financial statements or communications to the public;
(iii)	engage in any act, practice, or course of business which operates or would operate as a fraud or deceit upon any Fund or its shareholders;
(iv)	engage in any manipulative practice with respect to any Fund;
(v)	use his or her personal influence or personal relationships to influence any business decision, investment decisions, or financial reporting by a Fund whereby the Covered Officer would benefit personally to the detriment of the Fund or its shareholders;
(vi)	intentionally cause a Fund to fail to comply with applicable laws, rules and regulations, including failure to comply with the requirement of full, fair, accurate, understandable and timely disclosure in reports and documents that a Fund files with, or submits to, the SEC and in other public communications made by the Fund;
(vii)	intentionally mislead or omit to provide material information to the Fund’s independent auditors or to the Board of Trustees/Directors or the officers of the Fund or its investment adviser in connection with financial reporting matters;
(viii)	fail to notify the Code Administrator or the Chief Executive Officer of the Fund or its investment adviser promptly if he or she becomes aware of any existing or potential violations of this Code or applicable laws;
(ix)	retaliate against others for, or otherwise discourage the reporting of, actual or apparent violations of this Code; or
(x)	fails to acknowledge or certify compliance with this Code if requested to do so.

3. Reports of Conflicts of Interests

               If a Covered Officer becomes aware of a conflict of interest under this Code or, to the Covered Officer’s reasonable belief, the appearance of one, he or she must immediately report the matter to the Code’s Administrator. If the Code Administrator is involved or believed to be involved in the conflict of interest or appearance of conflict of interest, the Covered Officer shall report the matter directly to the OFI’s Chief Executive Officer.

               Upon receipt of a report of a conflict, the Code Administrator will take prompt steps to determine whether a conflict of interest exists. If the Code Administrator determines that an actual conflict of interest exists, the Code Administrator will take steps to resolve the conflict. If the Code Administrator determines that the appearance of a conflict exists, the Code Administrator will take appropriate steps to remedy such appearance. If the Code Administrator

determines that no conflict or appearance of a conflict exists, the Code Administrator shall meet with the Covered Officer to advise him or her of such finding and of his or her reason for taking no action. In lieu of determining whether a conflict or appearance of conflict exists, the Code Administrator may in his or her discretion refer the matter to the Fund’s Board of Trustees/Directors.

4. Waivers

          Any Covered Officer requesting a waiver of any of the provisions of this Code must submit a written request for such waiver to the Code Administrator, setting forth the basis of such request and all necessary facts upon which such request can be evaluated. The Code Administrator shall review such request and make a written determination thereon, which shall be binding. The Code Administrator may in reviewing such request, consult at his discretion with legal counsel to OFI or to the Fund.

          In determining whether to waive any of the provisions of this Code, the Code Administrator shall consider whether the proposed waiver:

(i) is prohibited by this Code;

(ii) is consistent with honest and ethical conduct; and

(iii) will result in a conflict of interest between the Covered Officer’s personal and professional obligations to a Fund.

          In lieu of determining whether to grant a waiver, the Code Administrator in his or her discretion may refer the matter to the appropriate Fund’s Board of Trustees/Directors.

5. Reporting Requirements

     (a) Each Covered Officer shall, upon becoming subject to this Code, be provided with a copy of this Code and shall affirm in writing that he or she has received, read, understands and shall adhere to this Code.

     (b) At least annually, all Covered Officers shall be provided with a copy of this Code and shall certify that they have read and understand this Code and recognize that they are subject thereto.

     (c) At least annually, all Covered Officers shall certify that they have complied with the requirements of this Code and that they have disclosed or reported any violations of this Code to the Code Administrator or the Chief Executive Officer of the Fund or its investment adviser.

     (d) The Code Administrator shall submit a quarterly report to the Board of Trustees/Directors of each Fund containing (i) a description of any report of a conflict of interest or apparent conflict and the disposition thereof; (ii) a description of any request for a waiver from this Code and the disposition thereof; (iii) any violation of the Code that has been reported or found and the sanction imposed; (iv) interpretations issued under the Code by the Code Administrator; and (v) any other significant information arising under the Code including any proposed amendments.

     (e) Each Covered Officer shall notify the Code Administrator promptly if he or she knows of or has a reasonable belief that any violation of this Code has occurred or is likely to occur. Failure to do so is itself a violation of this Code.

     (f) Any changes to or waivers of this Code, including “implicit” waivers as defined in applicable SEC rules, will, to the extent required, be disclosed by the Code Administrator or his or her designee as provided by applicable SEC rules.²

6. Annual Renewal

          At least annually, the Board of Trustees/Directors of each Fund shall review the Code and determine whether any amendments (including any amendments that may be recommended by OFI or the Fund’s legal counsel) are necessary or desirable, and shall consider whether to renew and/or amend the Code.

7. Sanctions

          Any violation of this Code of Ethics shall be subject to the imposition of such sanctions by OFI as may be deemed appropriate under the circumstances to achieve the purposes of this Code and may include, without limitation, a letter of censure, suspension from employment or termination of employment, in the sole discretion of OFI.

8. Administration and Construction

(a)	The administration of this Code of Ethics shall be the responsibility of OFI’s General Counsel or his designee as the “Code Administrator” of this Code, acting under the terms of this Code and the oversight of the Trustees/Directors of the Funds.
(b)	The duties of such Code Administrator will include:

(i)	Continuous maintenance of a current list of the names of all Covered Officers;
(ii)	Furnishing all Covered Officers a copy of this Code and initially and periodically informing them of their duties and obligations thereunder;
(iii)	Maintaining or supervising the maintenance of all records required by this Code, including records of waivers granted hereunder;

² An “implicit waiver” is the failure to take action within a reasonable period of time regarding a material departure from a provision of this Code that has been made known to the General Counsel, the Code Administrator, and an executive officer of the Fund or OFI.

(iv)	Issuing interpretations of this Code which appear to the Code Administrator to be consistent with the objectives of this Code and any applicable laws or regulations;
(v)	Conducting such inspections or investigations as shall reasonably be required to detect and report any violations of this Code, with his or her recommendations, to the Chief Executive Officer of OFI and to the Trustees/Directors of the affected Fund(s) or any committee appointed by them to deal with such information; and
(vi)	Periodically conducting educational training programs as needed to explain and reinforce the terms of this Code.

          (c) In carrying out the duties and responsibilities described under this Code, the Code Administrator may consult with legal counsel, who may include legal counsel to the applicable Funds, and such other persons as the Administrator shall deem necessary or desirable. The Code Administrator shall be protected from any liability hereunder or under any applicable law, rule or regulation, for decisions made in good faith based upon his or her reasonable judgment.

9. Required Records

     The Administrator shall maintain and cause to be maintained in an easily accessible place, the following records for the period required by applicable SEC rules (currently six years following the end of the fiscal year of OFI in which the applicable event or report occurred):

(a)	A copy of any Code which has been in effect during the period;
(b)	A record of any violation of any such Code and of any action taken as a result of such violation, during the period;
(c)	A copy of each annual report pursuant to the Code made by a Covered Officer during the period;
(d)	A copy of each report made by the Code Administrator pursuant to this Code during the period;
(e)	A list of all Covered Officers who are or have been required to make reports pursuant to this Code during the period, plus those person(s) who are or were responsible for reviewing these reports;
(f)	A record of any request to waive any requirement of this Code, the decision thereon and the reasons supporting the decision; and
(g)	A record of any report of any conflict of interest or appearance of a conflict of interest received by the Code Administrator or discovered by the Code Administrator during the period, the decision thereon and the reasons supporting the decision.

10. Amendments and Modifications

     Other than non-substantive or administrative changes, this Code may not be amended or modified unless approved or ratified by the Board of Trustees/Directors of each Fund.

11. Confidentiality.

     This Code is identified for the internal use of the Funds and OFI. Reports and records prepared or maintained under this Code are considered confidential and shall be maintained and protected accordingly to the extent permitted by applicable laws, rules and regulations. Except as otherwise required by law or this Code, such matters shall not be disclosed to anyone other than the Trustees/Directors of the affected Fund(s) and their counsel, the independent auditors of the affected Funds and/or OFI, and to OFI, except as such disclosure may be required pursuant to applicable judicial or regulatory process.

Dated as of: June 25, 2003, as revised August 30, 2006.

Exhibit A

Positions Covered by this Code of Ethics for Senior Officers

Each Oppenheimer or Centennial fund
Principal Executive Officer
Principal Financial Officer
Treasurer
Assistant Treasurer

Personnel of OFI, who by virtue of their jobs perform critical financial and accounting functions for OFI on behalf of a Fund, including:
Chief Financial Officer
Treasurer
Senior Vice President/Fund Accounting
Vice President/Fund Accounting

EX-99.CERT

Exhibit 99.CERT

Section 302 Certifications

CERTIFICATIONS

I, John V. Murphy, certify that:

1.	I have reviewed this report on Form N-CSR of Centennial Money Market Trust;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;
3.	Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;
4.	The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a)	Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;
(b)	Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;
(c)	Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and
(d)	Disclosed in this report any change in the registrant’s internal control over financial reporting 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 registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of Trustees (or persons performing the equivalent functions):

(a)	All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and
(b)	Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: 08/11/2009

/s/ John V. Murphy John V. Murphy
Principal Executive Officer

Exhibit 99.CERT

Section 302 Certifications

CERTIFICATIONS

I, Brian W. Wixted, certify that:

1.	I have reviewed this report on Form N-CSR of Centennial Money Market Trust;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;
3.	Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;
4.	The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a)	Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;
(b)	Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;
(c)	Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and
(d)	Disclosed in this report any change in the registrant’s internal control over financial reporting 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 registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of Trustees (or persons performing the equivalent functions):

(a)	All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and
(b)	Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: 08/11/2009

/s/ Brian W. Wixted Brian W. Wixted
Principal Financial Officer

EX-99.906CERT

EX-99.906CERT

Section 906 Certifications

CERTIFICATION PURSUANT TO 18 U.S.C SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

John V. Murphy, Principal Executive Officer, and Brian W. Wixted, Principal Financial Officer, of Centennial Money Market Trust (the “Registrant”), each certify to the best of his knowledge that:

1.	The Registrant’s periodic report on Form N-CSR for the period ended 06/30/2009 (the “Form N-CSR”) fully complies with the requirements of Section 15(d) of the Securities Exchange Act of 1934, as amended; and
2.	The information contained in the Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Registrant. This certification is being furnished to the Commission solely pursuant to 18 U.S.C. § 1350 and is not being filed as part of the Form N-CSR filed with the Commission.

Principal Executive Officer	Principal Financial Officer
Centennial Money Market Trust	Centennial Money Market Trust
/s/ John V. Murphy	/s/ Brian W. Wixted
John V. Murphy	Brian W. Wixted
Date: 08/11/2009	Date: 08/11/2009