Frankie Thomas appeared in 35 movies, including "A Dog of Flanders", "Tim Tyler's Luck" (as Tim Tyler), "Boys Town", and "The Major and the Minor" and many Nancy Drew movies with Bonita Granville.

During World War II, he spent five years in the Navy. When he returned to New York after his tour of duty, he worked steadily in radio, doing over 1500 shows. As dramatic radio waned, Frankie switched moved into the world of television. He did guest appearances on all the shows of the period including "Studio One" and the first five-days-a-week soap opera "A Woman to Remember".

It was his stage work and his experience in a daily show that Frankie believed helped him get the lead in "Tom Corbett, Space Cadet" in 1950.

Not long after the end of the "Tom Corbett" series, Frankie left the world of acting to teach bridge.