Peel Regional Police media tweeted that one car apparently drove into a store, then later struck several other vehicles at the intersection of Hurontario and Dundas. The car was reportedly a black Lincoln Navigator, and the female driver was among those sent to hospital.
A bus was also struck and a hydro pole was damaged, although power was not cut.
Emergency and hydro crews were on the scene of the crash, which occurred shortly after 6 p.m.
Police said those involved in the collision were lucky to walk away, and that most of the injuries were due to airbag deployments, or facial and neck injures from the impact.
The intersection is expected to remain closed for several hours.
Police have also ruled out drugs and alcohol as causes for the collision.