The artist's family moved to the USA in 1954, he grew up in Philadelphia and Syracuse NY. He studied at Le lycée Fustel-de-Coulanges in Strasbourg France (1967-68). In 1970 he returned to Montreal and completed art studies at Concordia University (BFA 1978) where he met his wife and fellow artist Teresa Cullen. By 1980 they were living and painting in Toronto at a studio on King St W and Dufferin. A regular exhibition career began with the Gadatsy Gallery in Yorkville (1980-87), followed by a switch to Bau-Xi Galleries in 1988 where he is still represented. Rising studio rental costs resulted in a move north of the city where the artists set up a country studio in Grey County. In 1997 after completing a MA degree at U of Toronto the couple moved to a new country studio in Oro-Medonte ON near Barrie where they continue to work. Marchessault's work has developed over the years from representational through abstraction to a blend of approaches displayed in exhibitions nationally and internationally. Galleries in both Canada and the US represent him, showing his work regularly. Marchessault paintings are widely collected with hundreds of works in both corporate and private collections.