Don Beddoe

 portrayed Santa Claus in the fourth season episode, "Humbug Not to Be Spoken Here" (1967).

Biography
Donald Theophilus Beddoe was an American character actor. Raised in New York City and Cincinnati, Ohio, Beddoe was the son of a professor at the Cincinnati Conservatory of Music who happened also to be the world-famous Welsh tenor, Dan Beddoe.

Although Don Beddoe intended a career in journalism, he took an interest in theatre and became involved first with amateur companies and then with professional theatre troupes. He debuted on Broadway in 1929 and kept up a decade-long career on the stage. Although said to have made some minor appearances in silent films, Beddoe made his real transfer to film work in 1938. He appeared in a wide range of supporting roles in literally scores of films, often as either a fast-talking reporter or as a mousey sort. He became one of the most readily familiar faces in Hollywood movies, despite remaining mostly unknown by name outside the industry. Following service in the Army Air Corps during the Second World War, he continued to work steadily in small roles, complementing them with television work. Despite advancing (and very ripe old) age, he remained quite active, supplementing his acting work with a second career in real estate.

Source
Don Beddoe on the Internet Movie Database. Retrieved on December 14, 2019.