Cuir Boilard

Large selection of leather at reasonable prices. I especially like going through their $10/15/20/30 rolls as you can often find some gems in there! Otherwise, the price per sq ft seem to range from $2-5/sq ft from what I’ve seen - although you do have to buy the entire hide (usually around 25 sq ft).

No-nonsense leather warehouse with really solid prices.
They don't sell any tools or findings, but a BIG selection of suade, thick, dyed, and painted leathers at better prices than Tandy Leather (I know Tandy closed their Montreal location, but even with free shipping Cuir Boilard beats them out)
Thick leathers at $1.75-4 a square foot, bulk bundles, and more.
Ya gotta buy the whole sheet or roll, but yeah, damn good prices for the quality!
As for buckles and D rings, not a big selection but pretty cheap for what ya get!

A great wholesale retail leather supplier with a large variety of leather. You'll typically need to buy the rolls/sides/bellies of leather, but it's more affordable than Tandy Leather Factory. No membership needed here. You'll find more coloured and lighter weight leathers at Cuir Boilard; whereas, Tandy will get you more natural vegetable tan leather and crafting leathers.