Orillia OPP is currently investigating a serious motor vehicle collision on Old Barrie Road in Oro-Medonte.
Just before 1:30 p.m., they were dispatched to Line 14 for a report of a two-vehicle collision.
One driver was transported to a local hospital, where they were then taken by Ornge to a Toronto-area trauma centre with life-threatening injuries. No other injuries were reported at the scene.
Old Barrie Road from Line 15 to Line 13 and Line 14 to Highway 11 have been closed for investigation.
Motorists and residents are asked to avoid the area.