In addition to his skills as an actor, he is also an accomplished writer. His work includes twelve "One Day at a Time" scripts he wrote for the series.
Has a Masters Degree in Political Philosophy.
After the Korean War, where he served in the Air Force as an Intelligence Officer and achieved the rank of First Lieutenant, he went to work at NBC in New York.
Pro wrestler The Honky Tonk Man based his gimmick on the character
(Dwayne Schneider) that Harrington played on One Day at a Time (1975).