Yves Bolduc, a former doctor, was travelling on the opposite side of the road when he arrived at the scene of the accident.
A vehicle had veered off a highway east of Montreal and slammed into an overpass support pillar.
Quebec provincial police say Bolduc tried to revive the driver but the man had already suffered fatal injuries in the crash.
Police haven't released any information about the driver.
The cause of the crash is under investigation.