His parents ran the Beaverton Hotel, and provided McMillan and his younger brother, Frank ("Cooch"), a worthy home and surroundings in which to grow up as youngsters.

Later in life, McMillan met his biological mother who refused to acknowledge him as her child, which was profoundly felt, and influenced his onstage performances, according to his actress/wife, Anne Louise Bannon.

After high school, McMillan moved to Toronto, Ontario and studied theater at Ryerson University but did not graduate, and instead, soon afterwards, joined the Stratford Festival as a young actor.

During this time, McMillan also performed in stage productions in and around Toronto,[5] which included a featured role in Inexpressible Island, a three-act dramatic play by David Young, in 1997.

You couldn’t take your eyes off him.”[2][3] McMillan was diagnosed with thyroid cancer in 2009 and after a remission later died of the disease on 17 February 2017 in Toronto at Princess Margaret Hospital at the age of 65.