Bert Lawrence Glennon (November 19, 1893 – June 29, 1967) was an American cinematographer and film director. He directed Syncopation (1929), the first film released by RKO Radio Pictures.
Glennon was born in Anaconda, Montana in 1893 and attended Stanford University, where he graduated in 1912. Before gaining fame in Hollywood, Glennon served as a pursuit pilot instructor during World War I. He began his work in film in 1912 as a stage manager for theater entrepreneur Oliver Morosco and then c. 1913 worked for Keystone and Famous Players, then was laboratory superintendent for Clune Film Corporation, for four years. In 1915 he did his first film as cinematographer The Stingaree (serial) and in 1928 he directed his first film The Perfect Crime.
Glennon was nominated for three Academy Awards in Best Cinematography for the films Stagecoach (1939), Drums Along the Mohawk (1939), and Dive Bomber (1941). He worked as a cinematographer on over 100 films for directors that included John Ford, André De Toth, Josef Von Sternberg, Raoul Walsh, and Cecil B. DeMille. His son James Glennon was also an Academy Award-nominated cinematographer.