The "Argo" star, 39, will hand the prize over in Santa Monica, California, reported Us magazine.
Affleck himself is a celeb Do Something nominee, along with Kristen Bell, Justin Bieber, Taylor Swift, Miley Cyrus, Nicole Richie, Neil Patrick Harris, Channing Tatum, Emma Stone and more.
The issue most important to the father of three is fostering development opportunities for residents of the war-torn Eastern Congo.
In 2009, Affleck founded the Eastern Congo Initiative to help the cause.
