Most will but you pay in US $$, not so good nowadays and the exchange rate will be further exacerbated by whatever your credit card exchange rate may be. I've heard that they can vary considerably, so check with your credit card carrier. You will also be on the hook for GST, PST, duty if applicable and brokerage fees.
1A auto parts, CARID, both sponsors here will ship cross border. The Hitch Store and Curt do although they may use Canadian based shipping points.
There are a few Canadian parts places like Parts Engine, www.partsengine.ca
and even Amazon.ca that have some Titan products and very often free shipping.
I suppose it all depends on what you're looking for and how deep your pockets are.