The son of a Nevada railroading engineer, Hobart Cavanaugh was educated in San Francisco and at the University of California. His friendships with such California-based actors as Charlie Ruggles and Walter Catlett gave Cavanaugh the impetus to enter the theatrical world. After several years on stage, Cavanaugh began his screen career with 1928's San Francisco Nights. Slight, balding and virtually chinless, Cavanaugh was ideally cast as a henpecked husband, a clerk, or a process server. He was signed to a Warners' contract in 1932, and appeared in several Busby Berkeley and Jimmy Cagney pictures. Thanks to his next-door-neighbor demeanor, Cavanaugh frequently appeared as humorist Robert Benchley's friend or co-worker in Benchley's one-reel MGM shorts of the 1930s. Occasionally, Cavanaugh played against his established image by popping up as the "hidden killer" in mystery films of the 1940s (e.g. Universal's Horror Island). Hobart Cavanaugh's final appearance, filmed just before his death, was as an unctuous undertaker in 20th Century-Fox's Stella (1950).