Bain studied acting at the Banff School of Fine Arts. Following service in the Canadian Army during WWII, he studied at the American Academy of Dramatic Arts in New York. He became a citizen of the United States in 1946.

Following work at the Stratford Shakespeare Festival in Canada, he won the choice role of Larry Slade in the famous 1956 Off-Broadway revival of Eugene O'Neill's The Iceman Cometh. He was soon on Broadway, in a short-lived play called Sixth Finger in a Five Finger Glove. He played a variety of roles in the original, ill-fated, 1957 Broadway production of Leonard Bernstein's musical Candide.

He found somewhat better acting opportunities Off-Broadway, getting regularly cast in many of the challenging stage works of the crowded the '60s New York stage.

Mr. Bain was an ordinary-looking man and tended to play ordinary people. As Bea Arthur's conservative, but well-meaning neighbor Arthur Harmon in the 1970s series "Maude," he indeed seemed like the sort of everyman you might end up with as a neighbor. His environs were a bit more rarified in "Diff'rent Strokes," which became a hit in 1978 on the strength of the magnetism of child star Gary Coleman.

As an activist for his profession, Mr. Bain played a critical role as one of the organizers of the Actors Federal Credit Union, a cooperatively run, not-for-profit financial institution, owned and controlled by its members. Bain served as the Credit Union's first president.

Source: Playbill.com