Gavin O'Connor will direct the film, which has a script by Bill Dubuque, about a government accountant who doubles as an assassin.
Lithgow will play Lamar Black, a tech magnate who hires Affleck's character to look into his company's finances.
Lithgow is a two-time Academy Award nominee for "The World According to Garp" and "Terms of Endearment." He won Tony Awards for The Changing Room and Sweet Smell of Success and was Tony-nominated for Requiem for a Heavyweight, M. Butterfly, Dirty Rotten Scoundrels and The Columnist.
Read Playbill.com's interview with Lithgow, where he shares his theatrical bucket list, here.
Lynette Howell and Mark Williams are producing, and Jamie Patricof and O'Connor are executive producing the film.
