I will be in Canada (Ontario) for one week before I plan to get married. I am travelling from the UK. Will this be enough time for me to get my marriage license, and is there anything that could delay this more than one week?
Yes. You need two pieces of government-issued ID. A passport and birth certificate are two examples the government mentioned. One must have your photo.
I would bring other ID too, such as your driver's license, just in case.