The Thirteenth Hour (aka:The 13th Hour) is a 1927 American silent mystery film produced and distributed by Metro Goldwyn Mayer and directed by Chester Franklin. The film stars Lionel Barrymore in a role where, as noted criminologist Professor Leroy, he dons a weird series of disguises to hide a dark secret. This was the first film where Barrymore was cast opposite talented dogs, and the first where he was cast as a serial killer.

A print of this film survives in 16mm.