All lanes on Highway 401 westbound just west of Guelph Line through Campbellville were closed Tuesday afternoon.
It happened around 4 p.m. when calls came into 570 NEWS regarding a collision and debris scattered across the roadway.
One vehicle went into the ditch in the area, and two other vehicles were reportedly involved as well.
Provincial police say one person was airlifted to hospital.
All lanes of the highway reopened after 7 p.m.