Crack-Up is a 1936 American film directed by Malcolm St. Clair. Peter Lorre plays a harmless, half-addled aircraft enthusiast who is actually a ruthless spy desperate to get his hands on the blueprints for an experimental aircraft for a trans-Atlantic flight. He faces off against Ace Martin, played by Brian Donlevy, the pilot of the aircraft, whose motives are spurred by feeling cheated by his own company. The supporting cast includes Helen Wood, Ralph Morgan and Thomas Beck.

Malcolm St. Clair was a Hollywood film director, writer, producer and actor.