I will be on holiday in the US soon and will be travelling in to Canada for a day. I am a British citizen. Will I need a visa? I shall be in the US on the Visa Waiver Program.
No, but I suggest you do not travel from the USA to Canada in a coach, I had an awful time with clearing Canadian customs, not because I was British, but because most other people where not, I waited 3 hours before we were allowed to drive on.