The DreamWorks Skg founders have made the huge handover to kick off the charity's new $350 million (£219 million) campaign.
Mptf board member and campaign co-chairman George Clooney announced the trio's donation at a press conference on Tuesday (16Oct12).
The actor said, "Steven Spielberg, Jeffrey Katzenberg and David Geffen are each legendary for their philanthropy and individually have made immeasurable impact on charities and organisations ranging from arts and culture, health care, education, film preservation and social services in our Hollywood community and around the nation.
"For them to make this unified commitment to Mptf only adds to that incredible record of generosity."
Katzenberg, who serves as chairman of the Mptf Foundation, added, "(My wife) Marilyn and I are so happy to join together with my partners and friends, Steven Spielberg and David Geffen, to support our industry's most important and valuable charitable organisation.
"Hopefully, with this gift, Mptf will get even closer to reaching its ambitious goal for its endowment campaign."
And Spielberg stated, "It becomes very personal when someone you know or have worked with is cared for, or a crew member is helped financially by Mptf. The mission 'we take care of our own' is suddenly very real and tangible, and so this new donation is an extension of what we have been doing for a number of years to support that mission."