The International Society of Olympic Historians is a non-profit organisation with the purpose of promoting and studying the Olympic Movement and the Olympic Games. This purpose is achieved primarily through research into their history, through the gathering of historical and statistical data concerning the Olympic Movement and Olympic Games, through the publication of the research via journals and other publications, and through the cooperation of the membership.

The International Society of Olympic Historians (ISOH) was formed as the result of a meeting in London, England in December 1991. The idea of forming an Olympic historical society had been the subject of correspondence – mainly between Bill Mallon (United States) and Ture Widlund (Sweden) – for many years. On Thursday, 5 December 1991, a group of potential members met at the Duke of Clarence, a small pub in the Kensington section of London. Those present were Ian Buchanan (Great Britain), Stan Greenberg (Great Britain), Ove Karlsson (Sweden), Bill Mallon (United States), Peter Matthews (Great Britain), David Wallechinsky (United States), and Ture Widlund (Sweden). The invited guests who sent regrets were: Anthony Bijkerk (Netherlands), Peter Diamond (United States), Pim Huurman (Netherlands), Erich Kamper (Austria), Volker Kluge (Germany), John Lucas (United States), and Wolf Lyberg (Sweden).

Currently, the ISOH has about 300 members from 50 nations. The ISOH publishes the Journal of Olympic History (formerly Citius, Altius, Fortius) three times a year.

From its inception to 2000, Ian Buchanan has been the president of the ISOH. In 2000, this function was taken over by Bill Mallon.

See also Sports history organizations