Educated by the Christian Brothers, Brian was apprenticed as a carpenter before emigrating at the age of 18 with his family to Canada, where he began acting in theatre and television.

[2] Phelan's notable film appearances include The Kitchen (1961), HMS Defiant (1962) and the title role in The Soldier's Tale (1964).

[citation needed] While he continued to work as a full-time actor in the 1960s, Phelan began his screenwriting career.

[4] His first television play was The Tormentors (1966), starring James Mason and Stanley Baker, produced by ATV.

[7][8] His stage plays include The Signalman's Apprentice (1971), which has been produced worldwide, Article Five, Paddy, News, and Soft Shoe Shuffle.