Robert Marchessault was born in Montreal in 1953. His early years (until 1969) were spent in the USA, (Philadelphia and Syracuse, NY). In the late 1960s his family relocated to France before returning to Canada in 1970 where he completed his fine arts studies at Concordia University (Montreal). He married the Canadian painter Teresa Cullen in 1977 and the couple settled in Toronto. There they painted professionally from a downtown studio until building a country studio in 1983 near Owen Sound, ON. In 1997 Marchessault completed a Master of Arts at the University of Toronto and the couple subsequently relocated and built two new studios close to Barrie, ON where they currently reside and work.

Marchessault continues to paint and exhibit nationally and internationally producing several exhibitions a year. His work is avidly collected and can be found world wide in many respected collections. The main galleries that represent his work are located in Toronto, Montreal, Vancouver, Seattle, Santa Fe, Ottawa and NewYork.