This is a Peregrine Falcon. You can see on his feet that he has a band so it is a bird that has been fledged locally.
The Canadian Peregrine Foundation says that the band is, "green tape and indicates a male. Most likely it is Euro from our Islington and Bloor nest at Sun Life. The only other candidate is Albus from our Yellow Pages nest at Markham and Milner in Scarborough. Euro is more likely as that nest is not far from Colonel Sam."
Thanks to Irene Cholewka for this photograph and the report.