Attended the American Academy of Dramatic Arts where his classmates included actor Charles Durning and comedian Don Rickles.
Began his series "Diff'rent Strokes" at the age of 55.
He has an identical twin brother named Bonar Bain
His identical twin Bonar once played a fictional "evil" twin to Conrad ("Hank Bain") in an episode of "SCTV", and played his brother Arnold in an episode of "Maude". Bonar went on to play a couple of roles in films on his own.
One of the first people to greet Victoria Winters as she arrives in Collinsport in the first episode of "Dark Shadows" (1966) was innkeeper Mr. Wells, played by Bain. The actor returned to Collinsport for three more episodes over the years; in his final appearance, in 1968, Mr. Wells fell victim to a werewolf.