Jim Bannon was a star athlete at Rockhurst College. After graduation, he became a sportscaster in Kansas City, and after 1938, in California. He began working as a radio actor and got small parts in movies. He was a movie stuntman in the early 1940s before starring in a detective movie series for Columbia, based on a radio show "I Love a Mystery." In 1949, he was given the title role of Red Ryder in the western series produced by Eagle Lion Productions. In the 1950s, he appeared in smaller character parts in westerns and on television.
He had a good physique but rarely got a chance to show it off in the movies. One exception came in Unknown World (1951) when he takes off his shirt in order to have more movement while swinging a sledgehammer.