The Face at the Window is a melodramatic detective play written by F. Brooke Warren and first produced in 1897. Set in Paris, its villain is a serial killer named Le Loup, who precedes his killings with a loud wolf-howl. He is pursued by the master detective Paul Gouffet. In an iconic scene, Gouffet causes a dead victim to complete the act of writing his murderer's name by passing an electric current through the arm muscles. A London performance in February 2002 was reported to last almost three hours and was accorded a most unflattering review.

The play gave rise to a succession of film versions.