Directed and produced by Affleck, the political thriller follows the true story of an unorthodox rescue mission conducted by the CIA during the 1979 Iran Hostage Crisis.
The plan to rescue six US Embassy staffers involves a fake science fiction film – titled Argo – which is the front for the hostages being smuggled out of the country.
The poster, released by Empire, shows Affleck in character as CIA operative Tony Mendez. Bryan Cranston, John Goodman and Alan Arkin also star.
Argo is co-produced by George Clooney, and written by scribe Chris Terrio.
Two new TV spots were released for the film earlier this month.
Argo will play at this year's BFI London Film Festival prior to its UK release on November 7.
Watch a trailer for Argo below: