Expo 67 officially opens in Montreal, Quebec, Canada with a large opening ceremony broadcast around the world. It opens to the public the next day.

The 1967 International and Universal Exposition or Expo 67, as it was commonly known, was a general exhibition, Category One World's Fair held in Montreal, Quebec, Canada, from April 27 to October 29, 1967. It is considered to be the most successful World's Fair of the 20th century with the most attendees to that date and 62 nations participating. It also set the single-day attendance record for a world's fair, with 569,500 visitors on its third day.

Expo 67 was Canada's main celebration during its centennial year. The fair had been intended to be held in Moscow, to help the Soviet Union celebrate the Russian Revolution's 50th anniversary; however, for various reasons, the Soviets decided to cancel, and Canada was awarded it in late 1962.

The project was not well supported in Canada at first. It took the determination of Montreal's mayor, Jean Drapeau, and a new team of managers to guide it past political, physical and temporal hurdles. Defying a computer analysis that said it could not be done, the fair opened on time.After Expo 67 ended in October 1967, the site and most of the pavilions continued on as an exhibition called Man and His World, open during the summer months from 1968 until 1984. By that time, most of the buildings—which had not been designed to last beyond the original exhibition—had deteriorated and were dismantled. Today, the islands that hosted the world exhibition are mainly used as parkland and for recreational use, with only a few remaining structures from Expo 67 to show that the event was held there.