The Unknown is a 1946 American mystery film directed by Henry Levin made by Columbia Pictures as the third and final part of its I Love a Mystery series based on the popular radio program. The previous films were I Love a Mystery (1945) and The Devil's Mask (1946).

The film is a loose adaptation of the I Love a Mystery radio episode Faith, Hope, and Charity, Sisters, which was remade in a later version of the radio series, in '49, as The Thing That Cries in the Night, starring Russell Thorson, Jim Boles, and Tony Randall as the private detectives, and Mercedes MacCambridge as the stewardess and Cherry (Charity).

It is also known as The Coffin.