The Academy Awards announced Thursday that the Argo director, 40, will join fellow nominees Jessica Chastain and Jennifer Lawrence as presenters for the Feb. 24 show.
Affleck is a nominee as a producer of Argo, which is up for Best Picture. Chastain, 35, and Lawrence, 22, are both competing in the Best Actress category – for Zero Dark Thirty and Silver Linings Playbook, respectively.
All three are second-time nominees. Chastain and Lawrence received earlier nods for The Help and Winter's Bone. Affleck won the only other time he was nominated, picking up the Oscar for Best Original Screenplay in 1998 for Good Will Hunting.
The announcement follows Wednesday's news that Best Actress winners Halle Berry, Sandra Bullock, Nicole Kidman and Reese Witherspoon will also take the stage.
The Academy has another announcement to make Friday at 12 p.m. ET. To get the news, check Oscar.com or download the official Oscars app, which offers trailers, videos, photos, games and more.
The 85th annual Academy Awards will air live on Sunday, Feb. 24, on ABC from the Dolby Theatre in Hollywood.