1940 Summer Olympics — Games of the XII Olympiad (cancelled)

The 1940 Summer Olympics, officially designated the Games of the XII Olympiad, were scheduled but ultimately never held. The story of the 1940 Games reflects the increasing international tensions of the late 1930s: an emerging host in Asia, a later reassignment in Europe, and the final blow dealt by the global conflict that began in 1939.

Initial award and withdrawal. At the 1936 International Olympic Committee session the Games were awarded to Tokyo in Japan, which would have marked the first time the modern Summer Olympics were staged in Asia. As Japan became militarily engaged on the Asian mainland, Japanese organizers withdrew their offer in 1938, citing the strains created by the Second Sino-Japanese War.

Reassignment to Helsinki. After Tokyo's withdrawal the International Olympic Committee selected Helsinki in Finland as the replacement host. Helsinki had been a notable candidate and preparation began in the late 1930s, but fresh international crises soon overwhelmed those plans.

Cancellation and context. The outbreak and expansion of World War II made international competition impossible: travel, safety and national priorities were dominated by war, and the IOC formally cancelled the Games. The cancellation of 1940 interrupted the Olympic sequence until the next Summer Games were held in London in 1948; the 1944 Games were likewise cancelled for the same reasons.