It depends on what you are looking for. I am not familiar with Canadian reptile breeders, but browsing any sites similar to Craigslist will allow you to find people rehoming animals near you. Looking in Facebook groups will also allow you to find animals being rehomed as well as find breeders in your area. Asking in those local groups will also allow other locals to send you to breeders. Just be sure to do a background check on them before purchasing any animals.
I've had good working relationships with Undergound Reptiles out of Florida and Josh's Frogs out of Michigan, and as someone else mentioned Morph Market is a good option to and if you choose that route you also have the chance of building one on one relationship with small time hobbyist and breeders for the future of your collection.
If you are in BC, mostly just geckos is a great breeder who I have bought frogs from. Although they have mostly just dart frogs so if you aren't looking for those they probably don't have what you want. Online reptile stores are hard to find in canada and shipping across province borders is often difficult. I looked for facebook groups about breeding the kind of reptile I want, and then looked for local breeders through them. Craigslist or kijiji are both great for finding reptiles for rehoming. I don't recommend buying through pet stores or large breeders as many can be shady and the health of the animals is not guaranteed to be as good as a hobby breeder.
