The race distance varied from 40 km to 42 kilometres (26 mi) in the early editions as it was typically based upon the distance between two points that the organisers felt were suitable. The 1908 London Olympics marked the introduction of the now standard distance of 26 miles, 385 yards (42.195 km). However, it was not until the 1924 Paris Olympics that this distance became the standard at the Olympics.
The Olympic marathon proved immediately popular in the Western world and quickly spawned numerous long-running annual races, including the Boston Marathon in 1897, the Tour de Paris Marathon in 1902, the Yonkers Marathon in 1907, and the London Polytechnic Marathon in 1909. Such marathons played a key role in the expansion of the road running movement internationally over the course of the 20th century.
The Olympic records for the event are 2:06:32 hours for men, set by Samuel Wanjiru in 2008, and 2:23:07 hours for women, set by Tiki Gelana in 2012. The men's marathon world record has been improved several times at the Olympics: in 1908, 1920, and then at successive Olympics by Abebe Bikila in 1960 and 1964. Abebe Bikila and Waldemar Cierpinski are the only athletes to have won two Olympic gold medals in the marathon. No athlete has won more than two medals of any colour. Ethiopia has won the most gold medals in the event, with six, while the United States has the greatest medal total with twelve overall.
The 1906 Intercalated Games were held in Athens and at the time were officially recognised as part of the Olympic Games series, with the intention being to hold a games in Greece in two-year intervals between the internationally held Olympics. However, this plan never came to fruition and the International Olympic Committee (IOC) later decided not to recognise these games as part of the official Olympic series. Some sports historians continue to treat the results of these games as part of the Olympic canon.
At this event a men's marathon was held over 41.86 km and Canada's Billy Sherring won the competition. John Svanberg, the runner-up in the 1906 5-mile race, was also runner-up in the marathon. American William Frank was the bronze medalist.
^The IOC attributes Théato's medal to France, despite later sources finding that his nationality was Luxembourgish.
^Corey is described in the 1904 Games report as a "Frenchman wearing the colors of the Chicago Athletic Association", but the IOC attributes his medal to the United States.
^ abBoth Sohn Kee-chung (Son Kitei) and Nam Sung-yong (Nan Shoryu) were from Korea. The IOC attributes both medals to Japan due to Korea being a Japanese colony at the time. All Korean Olympians during the Japanese colonial rule could only participate in the games as a representative of Japan and had to compete with Japanese names instead of their original Korean names. However, some sources still refer to Son Kitei as the first Korean to win an Olympic marathon today.