William Paterson Ewen was born in 1925 in Montreal, Quebec. Interested in art from a young age, he began by sculpting small figures in wax, and at thirteen petitioned his mother to hang art on the previously unadorned walls of the Ewen residence. Beginning in 1944, Ewen served in a reconnaissance regiment on the Western Front (World War II), but was not involved in active combat. Upon his return to Canada, he enrolled in McGill University. He studied geology, but after his first year he began to struggle with depression, and sought relief in copying magazine covers and sketching the landscape around Canadian Officers' Training Corps at Saint-Gabriel-de-Valcartier where he had re-enlisted for the summer. When he returned to school in the fall, Ewen signed up for a figure-drawing course taught by John Goodwin Lyman. The experience was, as Ewen recalls it, unpleasant. The next year he transferred to the School of Art and Design at the Montreal Museum of Fine Arts, where he studied under Goodridge Roberts, Arthur Lismer, Moses Reinblatt, and Jacques de Tonnancour. Ewen sometimes recalled this period, caught up in Goodridge's orbit and the "sympathetic atmosphere," of the program, as "the happiest days of [his] life.