Fidelity Money Market Trust

Fund/Ticker

Retirement Money Market Portfolio/FRTXX

Summary Prospectus

October 30, 2010

Fund Summary

Fund:
Retirement Money Market Portfolio

Investment Objective

The fund seeks to obtain as high a level of current income as is consistent with the preservation of capital and liquidity.

Fee Table

The following table describes the fees and expenses that may be incurred when you buy and hold shares of the fund.

Shareholder fees
(fees paid directly from your investment) None

Annual fund operating expenses
(expenses that you pay each year as a % of the value of your investment)

Management fee	0.42%
Distribution and/or Service (12b-1) fees	None
Other expenses	0.00%
Total annual fund operating expenses	0.42%

This example helps compare the cost of investing in the fund with the cost of investing in other mutual funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

1 year	$ 43
3 years	$ 135
5 years	$ 235
10 years	$ 530

Principal Investment Strategies

• Investing in U.S. dollar-denominated money market securities of domestic and foreign issuers and repurchase agreements.
• Potentially entering into reverse repurchase agreements.
• Investing more than 25% of total assets in the financial services industries.
• Investing in compliance with industry-standard regulatory requirements for money market funds for the quality, maturity, and diversification of investments.

Summary Prospectus

Principal Investment Risks

• Interest Rate Changes. Interest rate increases can cause the price of a money market security to decrease.
• Foreign Exposure. Entities located in foreign countries can be affected by adverse political, regulatory, market, or economic developments in those countries.
• Financial Services Exposure. Changes in government regulation and interest rates and economic downturns can have a significant negative effect on issuers in the financial services sector, including the price of their securities or their ability to meet their payment obligations.
• Issuer-Specific Changes. A decline in the credit quality of an issuer or a provider of credit support or a maturity-shortening structure for a security can cause the price of a money market security to decrease.

An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Although the fund seeks to preserve the value of your investment at $1.00 per share, it is possible to lose money by investing in the fund.

Performance

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year. Past performance is not an indication of future performance.

Visit www.fidelity.com for updated return information.

Year-by-Year Returns

Calendar Years	2000	2001	2002	2003	2004	2005	2006	2007	2008	2009
	6.28%	4.05%	1.57%	0.89%	1.07%	2.96%	4.82%	5.12%	2.93%	0.63%

During the periods shown in the chart:	Returns	Quarter ended
Highest Quarter Return	1.61%	September 30, 2000
Lowest Quarter Return	0.04%	December 31, 2009
Year-to-Date Return	0.01%	September 30, 2010

Summary Prospectus

Fund Summary - continued

Average Annual Returns

For the periods ended December 31, 2009	Past 1 year	Past 5 years	Past 10 years
Retirement Money Market Portfolio	0.63%	3.28%	3.01%

Investment Advisers

Fidelity Management & Research Company (FMR) is the fund's manager. Fidelity Investments Money Management, Inc. (FIMM) and other investment advisers serve as sub-advisers for the fund.

Purchase and Sale of Shares

You may buy or sell shares of the fund through a retirement account or through an investment professional. You may buy or sell shares in various ways:

Internet

www.fidelity.com

Phone

For Individual Accounts (investing through a retirement plan sponsor or other institution), refer to your plan materials or contact that institution directly.

For Retirement Plan Level Accounts:

Corporate Clients 1-800-962-1375

"Not for Profit" Clients 1-800-343-0860

For Financial and Other Institutions:

1-877-208-0098

For Rollover IRAs:

1-800-544-6666

Mail

Fidelity Institutional Retirement Services Company
P.O. Box 650488
Dallas, TX 75265-0488

TDD - Service for the Deaf and Hearing Impaired

1-800-544-0118

The price to buy one share of the fund is its net asset value per share (NAV). Your shares will be bought at the NAV next calculated after your order is received in proper form.

The price to sell one share of the fund is its NAV. Your shares will be sold at the NAV next calculated after your order is received in proper form.

The fund is open for business each day the New York Stock Exchange (NYSE) is open. Even if the NYSE is closed, the fund will be open for business on those days on which the Federal Reserve Bank of New York (New York Fed) is open, the primary trading markets for the fund's portfolio instruments are open, and the fund's management believes there is an adequate market to meet purchase and redemption requests.

Initial Purchase Minimum	$100,000
For Fidelity Rollover IRA and Keogh accounts	$500

The fund may waive or lower purchase minimums in other circumstances.

Summary Prospectus

Tax Information

Distributions you receive from the fund are subject to federal income tax and generally will be taxed as ordinary income or capital gains, and may also be subject to state or local taxes, unless you are investing through a tax-advantaged retirement account (in which case you may be taxed later, upon withdrawal of your investment from such account).

Payments to Broker-Dealers and Other Financial Intermediaries

The fund, FMR, Fidelity Distributors Corporation (FDC), and/or their affiliates may pay intermediaries, including banks, broker-dealers, retirement plan sponsors, administrators, or service-providers (who may be affiliated with FMR or FDC), for the sale of fund shares and related services. These payments may create a conflict of interest by influencing your intermediary and your investment professional to recommend the fund over another investment. Ask your investment professional or visit your intermediary's web site for more information.

Summary Prospectus

FDC is a member of the Securities Investor Protection Corporation (SIPC). You may obtain information about SIPC, including the SIPC brochure, by visiting www.sipc.org or calling SIPC at 202-371-8300.

Fidelity Investments & (Pyramid) Design is a registered trademark of FMR LLC.

The third party marks appearing above are the marks of their respective owners.

1.917756.100 RMM-sum-1010