[1] Barrette ran as a Conservative candidate in the provincial district of Joliette in the 1935 election but lost.

Barrette served as Minister of Labour in the Cabinets of Maurice Duplessis and Paul Sauvé from August 30, 1944, to January 8, 1960.

After Sauvé's death, Barrette succeeded him as leader of the Union Nationale and as Premier of Quebec on January 8, 1960.

At the June 1960 election, he lost to Jean Lesage's Quebec Liberal Party.

He resigned as both Leader of the Union Nationale and member of the National Assembly on September 15, 1960, and later served as Canadian ambassador to Greece from April 4, 1963, to July 12, 1966.