Might also be a red tailed hawk, but it is hard to tell. There are a few living by me in Toronto. He's gorgeous!

You didn't post where you saw it nor what time of year, so I'll just throw out a hawk that I know as a possible from my area. Though, I'm sure it could be others.
Red shouldered, immature.

Sorry, I saw them in northern Indiana, so I guess it would be an Eastern Red-shouldered, but from what I see they have dark breast streaking. Do the immature have a bare white belly like these do? In Florida it looks like the streaking is less evident.

It does indeed vary some with local strains. That kinda makes it really hard to identify them.

Yes, and confusing for those starting out too. Both Peterson's guide to Hawks and Wheeler & Clark's A Photographic Guide to North American Raptors state that the Fuertes and Krider Red-tailed Hawk subspecies/type lacks the dark belly band typical of the common Red-Tailed Hawk. In Sibley's big book it is stated that "Perched light morph Red-tailed hawks of all ages typically show a dark "belly-band" and a V - shaped pattern of white speckling on the back, both of which are excellent clues for identification." Couldn't see the back, but these descriptions along with the absence of the dark upper breast coloration present in the Swainson's and the lack of the feathers going all the way down to the feet in the Ferruginous tend to rule out those other two kinds of hawks which have a white belly. So I think it is may be one of those types of RTH although Krider's does seem to be almost an albino. Really neat hawks though. The chest looks like a pillow. Someone should start making pillows out of feathers instead of polyurethane.

Red-tailed hawk, wind-blown stage.