He fought in World War I as a tank commander, studied at Université Laval, and was admitted to the bar of Quebec in 1920.

He soon formed an alliance with Maurice Duplessis's Quebec Conservative Party to contest the 1935 provincial election.

Gouin withdrew his support from Duplessis on June 18, 1936, but most members of the ALN caucus sided with Duplessis and joined with his Conservative caucus, which formally merged into the Union Nationale party, which not long afterwards won the 1936 election.

He helped found the Bloc populaire canadien in 1942 but left it in early 1944 when André Laurendeau was chosen to lead the Quebec wing of the party.

In 1952 he succeeded Madame Athanase David as the President of the Montreal Festivals, a post he held through 1956.