OppenheimerFunds, Inc.
                          Two World Financial Center
                        225 Liberty Street, 11th Floor
                           New York, NY 10281-1008



October 29, 2008

VIA EDGAR

Securities and Exchange Commission
Mail Stop 0-7, Filer Support
6432 General Green Way
Alexandria, VA 22312

      Re:  Centennial Money Market Trust (the "Registrant")
           Reg. No. 2-65245; File No. 811-02945

To the Securities and Exchange Commission:

      Pursuant to Rule 497(j) under the Securities Act of 1933, as amended
(the "Securities Act"), I hereby represent that the form of Prospectus and
Statement of Additional Information that would have been filed pursuant to
Rule 497(c) under the Securities Act would not have differed from that
contained in Post-Effective Amendment No. 42 to the Registrant's Registration
Statement on Form N-1A, which was filed electronically with the Securities
and Exchange Commission on October 24, 2008.

                                          Sincerely,

                                          /s/ Kathleen T. Ives
                                          ------------------------------------
                                          Kathleen T. Ives
                                          Vice President & Deputy General
                                          Counsel
                                          (303) 768-3331
                                          kives@oppenheimerfunds.com


cc:  Bell, Boyd & Lloyd
     Gloria LaFond
     Nancy S. Vann