In 1955, he appeared as Samuel Mason on ABC's Disneyland miniseries Davy Crockett, starring Fess Parker. From 1957–1959, Mills co-starred with Rex Reason in the syndicated western series Man Without a Gun. He portrayed Marshal Frank Tillman. Reason played his friend, Adam MacLean, Editor of the Yellowstone Sentinel newspaper. In the 1965 Three Stooges film, The Outlaws Is Coming, Mills played Trigger Mortis.