Jean, 52, has taken Fort McMurray-Conklin away from Tory Advanced Education Minister Don Scott.
Jean did not hold a seat going into the election.
He has only had the Wildrose party's top job since March.
He won a leadership race that was needed after former leader Danielle Smith crossed the floor to the Progressive Conservative government.
Jean spent a decade as a backbencher in Conservative Prime Minister Stephen Harper's government.Suggest a correction