Does the "US data Sim" data work in Canada too?

Yes, it will provide data in Canada at £1.28pMB.

You may wish to review other Canadian data solutions at; www.dataroam.co.uk

you can use US  sim in Canada only if the phone in which you are going to use your sim is unlocked . if its locked to any network provider  you cant's use unless you unlock it .To unlock mobile phone visit Onlinegsmunlock.com .