The meeting took place in the Centre Block on Parliament Hill in Ottawa. Lennon and Ono had arrived in the city at 2am that morning, having travelled from Toronto via Montreal.
They arrived at the Parliament Building at 11am, with a scrum of photographers ready to snap the moment they met the Canadian PM. It was the only time Lennon and Ono were able to take their peace campaign directly to a world leader.
The meeting lasted for 51 minutes behind closed doors, although news cameras were on hand before and after. When they emerged, a reporter asked Lennon and Ono what had taken them so long. Ono replied that it was because they had all been enjoying the conversation.
Lennon added: "We spent about 50 minutes together, which was longer than he had spent with any head of state. If all politicians were like Mr Trudeau there would be world peace."
The couple also met health minister John Munro for almost two hours before flying back to Toronto, and from there to London, later that day.
Also on this day...
- 1999: An intruder breaks into George Harrison’s Hawaiian home
- 1964: Rehearsal: Another Beatles Christmas Show
- 1962: Live: Star-Club, Hamburg
- 1961: Live: Cavern Club, Liverpool (evening)
Want more? Visit the Beatles history section.