In reply to wawbanks:
The Niagara Escarpment- limestone - is close to Toronto. There are a number of different crags along this. They were originally developed as trad climbing, but now offer sport routes and mixed routes. Closest to Toronto are Rattlesnake Point, Buffalo Crag and Mt Nemo. It's mostly single pitch routes. A bit polished. Further north are other newer areas that were primarily developed as sport areas. The routes are described in a two volume guidebook.
I have climbed at the crags I mentioned - I was a grad student at a nearby university but in the 70s before the sport routes were developed.
There are also likely sport crags to the east of Toronto - lots of Canadian Shield granite. There is a big 400ft cliff called Bon Echo about three hours from Toronto but it's predominantly trad climbing, but it's likley other nearby areas have been developed as sport climbs. There are several FB groups for Ontario climbers and you could probably get info there