Paar signed as a contract player for Howard Hughes' RKO Pictures studio in the immediate postwar period, appearing as the emcee in the movie "Variety Time" (1948), a compilation of vaudeville sketches. He later recalled that RKO producers had trouble figuring out what kind of screen characters he could play until one of the executives dubbed him, "Kay Kyser popular bandleader of the time, with warmth." Another compared his leading man appearance with Alan Ladd. Paar projected a pleasant personality on film, and RKO called him back to emcee another filmed vaudeville show, "Footlight Varieties" (1951). He also appeared in the 1950 film "Walk Softly, Stranger", starring Joseph Cotten. In 1951, he played Marilyn Monroe's boyfriend in the 20th Century Fox film "Love Nest".