Sam Oosterhoff won the PC nomination Saturday night to become the party's candidate in Niagara West-Glanbrook.
The riding was vacated when former party leader Tim Hudak resigned last month and the byelection will be held Nov. 17, along with one in Ottawa-Vanier.
Oosterhoff was up against party president and former MP Rick Dykstra, as well as regional councillor Tony Quirk in seeking the nomination.
Oosterhoff is a student at Brock University and has worked as a legislative assistant in Parliament Hill.
PC Leader Patrick Brown says the byelection is an opportunity to share a ``positive message of change.''