In 1943, Thompson, known for his boy-next-door good looks, was signed by Universal Pictures. He played quiet, thoughtful teens in Universal's feature films, including a lead opposite singing star Gloria Jean in Reckless Age, earning $350 weekly. During 1946, Universal discharged most of its contract players; that same year, Thompson moved to MGM and his film roles steadily increased and improved with appearances in The Clock and the lead in Gallant Bess, MGM's first film in Cinecolor.