Scheer, 38, is a lawmaker from western Saskatchewan province who has pledged to reduce government spending and trim deficits.
After a year of campaigning, he defeated 12 other hopefuls at a suspenseful party meeting outside Toronto yesterday.
Scheer now faces the difficult task of uniting two deeply divided wings of the party ahead of the next election.
He succeeds interim leader Rona Ambrose, who took over from then prime minister Stephen Harper after his defeat in the 2015 elections.