MGM didn't want Robert Montgomery to do the film, and at its premiere at Grauman's Chinese screened a trailer disclaiming the film and warning the audience about the film's "spurious content." Despite this, the film was well-received by audiences and critics.
The filming location of Sherwood Forest in Southern California stood in for the English countryside. It's in the San Fernando Valley and today is part of a suburban neighborhood near California State University Northridge. At the time of the film, it was still rural agricultural land dotted with stately oaks and citrus groves.
Danny says he sailed twice around the Cape of Good Hope "before the mast" which refers to being a common sailor (not an officer), because the quarters for common sailors were in the front of the ship (the forecastle).
"Night Must Fall" premiered on stage in London at the Duchess Theatre on 31 May 1935, and featured Emlyn Williams as Dan; May Whitty as Mrs. Bramson; Angela Baddeley as Olivia Grayne; Kathleen Harrison as Mrs. Terence; Basil Radford as Hubert Laurie; and Matthew Boulton as Inspector Belsize. The play was produced by Miles Malleson, and directed by Williams. Angela Baddeley, Matthew Boulton, May Whitty, and Emlyn Williams would reprise their roles in the 1936 Broadway production.