Thousands of people have started to converge on the Mall ahead of tonight's Diamond Jubilee concert at Buckingham Palace.
Prime Minister Stephen Harper is to join them to take in the show, which features performances by Stevie Wonder, Elton John and Paul McCartney.
Union Jacks billow in downtown London, the streets are awash in bunting and storefronts feature photos of the Queen.
With rain forecast for the concert, many revellers are sporting ponchos and rain jackets to keep them as dry as possible during the show.
The occasional Canadian flag can be spotted in the massive sea of Union Jacks in the Mall, with some Canucks making the trip across the pond for the Queen's big party.
Harper will have an audience with the Queen later this week before heading to Paris and then home.