Frank Jenks, a wavy-haired American character actor and musician, was born to a father who was an advertising man and a mother who was a pianist. After his family settled in Los Angeles, he attended the University of Southern California, where he learned to play the trumpet, trombone, and clarinet. However, he eventually dropped out of college and pursued a career in music, leading a band on the West Coast vaudeville circuit.
He then transitioned to becoming a song-and-dance man, and later made his way to the legitimate stage and eventually to movies. Initially, he played orchestra leaders, a role that required little acting ability. However, he soon developed his skills as a comic actor, and his cinematic stock-in-trade became fast-talking reporters, droll Runyonesque henchmen, cabbies, grifters, cops, bartenders, and drunks.
Jenks was known for his improvisational abilities, often adding his own routines to varied comedy scripts. This earned him the nickname "off-the-cuff Jenks" in Hollywood. Throughout his career, he appeared in numerous supporting roles, often for Universal's B-team. He even managed to secure star billing in a series of forgotten potboilers made by Poverty Row outfit PRC during the 1940s.
In the early 1950s, Jenks became a regular guest performer on television, appearing in a wide range of shows, from Adventures of Superman to Perry Mason.