Here are some other projects he was involved in:
Television:
* The Army Game (1957-1961) - Played Sergeant-Major "Blossom"
* The Valiant Years (1961) - Played Sergeant-Major "Blossom"
* The Four Just Men (1960-1961) - Played Jacko
* Dixon of Dock Green (1955-1976) - Played various roles
* The Adventures of Robin Hood (1955-1960) - Played various roles
* The Adventures of William Tell (1955-1958) - Played various roles
* The Adventures of Sir Lancelot (1956-1957) - Played various roles
* The Prisoner (1967) - Played Number Two in the episode "Free for All"
Film:
* The Day the Earth Stood Still (1951) - Played a scientist
* The Black Knight (1954) - Played the King
* The Sea Shall Not Have Them (1954) - Played the Chief Petty Officer
* The Prisoner (1955) - Played the Captain
* The Cruel Sea (1953) - Played Lieutenant Commander
* The Square Ring (1953) - Played the manager
This is not an exhaustive list, but it encompasses some of his most notable work outside of Doctor Who. Hartnell's career spanned over 30 years and included many roles in both television and film.