It happened on Highway 21 between Concessions 7 and 9 Tuesday afternoon around 4:15.
Emergency crews arrived to find a pick up truck colliding with a motorcycle with two occupants on it.
A passenger on the motorcycle was taken to a local hospital and later died.
The driver of the motorcycle was airlifted to a London hospital with serious injuries.
The section was closed to traffic for several hours as members of the OPP Traffic Incident Management and Enforcement (TIME) team were assisting in the investigation.
Investigators want to speak to anyone who may have witnessed the crash.