The crash occurred at about 1:30 a.m. Wednesday at the intersection of McLaughlin Road and Eglinton Avenue West.
The police cruiser collided with a car, which in turn caused that vehicle to hit a van, a Peel Regional Police spokesperson said.
The civilian drivers were taken to hospital with minor injuries and later released. The officer was not injured.
The Special Investigations Unit was initially called in, but are no longer probing the crash because no serious injuries were reported.