The men's marathon at the 1956 Summer Olympics in Melbourne, Australia was held on Saturday December 1, 1956. There were 46 participants from 23 nations, with 13 runners not completing the race. The maximum number of athletes per nation had been set at 3 since the 1930 Olympic Congress. The event was won by 1 minute 32 seconds by Alain Mimoun of France, the nation's first Olympic marathon victory since 1928 and third overall. Yugoslavia took its first Olympic marathon medal with Franjo Mihalić's silver. Finland returned to the podium in the event for the first time since 1932 as Veikko Karvonen took bronze.

Alain Mimoun, born Ali Mimoun Ould Kacha, was a French long-distance runner who competed in track events, cross-country running and the marathon. He was the 1956 Olympic champion in the marathon. He is the most bemedalled French athletics sportsperson in history. In 1999, readers of the French athletics magazine Athlétisme Magazine voted him as the “French Athlete of the 20th Century”.