The Boston boy helped to raise 156,250 pounds at the glitzy night held at filmmaker J.J. Abrams' production base in Santa Monica, California Monday.
Consumer advocate Elizabeth Warren, a Harvard Law professor, is fighting for the late Ted Kennedy's Massachusetts vacant office.
Affleck's actor friend Matt Damon and fellow Boston native John Krasinski were billed as co-hosts of the event, dubbed A Massachusetts Evening. However, they couldn't attend it due to work commitments.
Apart from Affleck and his wife Jennifer Garner, other celebrities who attended the fundraiser included Reese Witherspoon, Zach Braff, Dana Delany and Tobey Maguire, while directors Steven Spielberg and Rob Reiner and movie moguls Jeffrey Katzenberg and Harvey Weinstein were among those who contributed to the success of the event.