In 1905, Ouimet married Hortense Mousseau, the sister of Joseph-Octave Mousseau.He was elected to Parliament at the Vaudreuil—Soulanges riding in a by-election on 21 March 1922.
After serving for the remainder of the 14th Canadian Parliament, Ouimet left federal politics and did not seek another term in the 1925 election.