Simple question, but unfortunately I’ve heard this pronounced differently.
Let’s take the case titled “R v. Edwards.”
I’ve heard people pronounce it as “Are v. Edwards,” “The Queen v. Edwards” and “The Crown v. Edwards.” It seems to me that “The Crown” is most likely to be correct, but I’m not sure.
Actually, that should be “R.”, with a period there. It stands for “Rex”, Latin for ‘The King’ or ‘The Queen’, or even ‘The Crown’ (to use a gender-neutral term). [Why they would bother to abbreviate a 3-letter word is beyond me.]
But I think GorillaMan is correct; the current usage is to say “Canada” in such cases.