As long as you have a US bank-issued credit card that has been approved for Apple Pay, you can setup it up to use in Canada or anywhere else in the world where NFC terminals are available.
Right here in Canada, numerous restaurant chains such as Tim Hortons have NFC-enabled terminals. Below is a demo of Apple Pay working successfully at a location in Vancouver as shared by iPhoneinCanada.ca reader Ellard.
The demo is the same as what you’ve already seen before from Apple—once it’s time to pay, just place your iPhone 6 or iPhone 6 Plus next to the terminal then authorize your purchase with Touch ID. Here’s another but this time at Subway:
However in this case you will be required to bring up your card using Passbook, but at some US retail locations, it should just appear on the lock screen.
You can find NFC-enabled merchants from MasterCard by downloading the nearby app. Want to try Apple Pay in Canada? All you need is a supported US-based credit card.