The 43-year-old actor, who dated Fey's character Liz Lemon in "30 Rock", will once again play her stiff British boyfriend in the film, The Hollywood Reporter said.
The Paul Weitz directed film is about an unmarried college admissions counsellor (Fey) who strikes up a romance with a man (Rudd) she knew when she was in school.
The film is expected to go on floors in May in New York.
Sheen most recently starred in Woody Allen's "Midnight in Paris" and "The Twilight Saga: Breaking Dawn Part 1".