The decisive body of the IOF is the members in General Assembly. A General Assembly may be either Ordinary or Extraordinary. The Ordinary General Assembly shall meet biennially. Each IOF member has the right to send three delegates to a General Assembly. Each member represented at the General Assembly, except for provisional members, has one vote.
The next IOF Ordinary General Assembly will take place in July 2024 in a hybrid format, in conjuction with the World Orienteering Championships in Scotland.
Since the IOF was founded in 1961, the IOF Congress and General Assembly has been held as follows:
| No. | Year | Venue |
| 1 | 1961 | Copenhagen, DEN |
| 2 | 1963 | Leipzig, GDR |
| 3 | 1965 | Kamtschia, BUL |
| 4 | 1967 | Mooserboden, AUT |
| 5 | 1969 | Budapest, HUN |
| 6 | 1971 | Kiljava, FIN |
| 7 | 1973 | Magglingen, SUI |
| 8 | 1975 | Bosön-Stockholm, SWE |
| 9 | 1977 | Innsbruck, AUT |
| 10 | 1980 | Malente, FRG |
| 11 | 1982 | Liége, BEL |
| 12 | 1984 | Maynooth, IRL |
| 13 | 1986 | Ry, DEN |
| 14 | 1988 | Torbole, ITA |
| 15 | 1990 | Cambridge, GBR |
| 16 | 1992 | Filzbach, SUI |
| 17 | 1994 | Varna, BUL |
| 18 | 1996 | Jerusalem, ISR |
| 19 | 1998 | Sintra, POR (ordinary General Assembly) and *Extraordinary General Assembly |
| 20 | 2000 | Graz, AUT |
| 2001 | Tampere, FIN** |
|
| 21 | 2002 | Fontainebleau, FRA |
| 22 | 2004 | Västerås, SWE (ordinary General Assembly) and *Extraordinary General Assembly |
| 23 | 2006 | Aarhus, DEN |
| 24 | 2008 | Prostejov, CZE |
| 25 | 2010 | Trondheim, NOR |
| 26 | 2012 | Lausanne, SUI |
| 27 | 2014 | Lavarone, ITA |
| 2015 | Inverness, GBR ** | |
| 28 | 2016 | Strömstad, SWE |
| 29 | 2018 | Prague, CZE |
| 30 | 2020 | Online conference |
| 2022 | Online conference *** | |
| 31 | 2022 | Triangle Region, DEN |
| 32 | 2024 | Edinburgh, GBR |
*An Extraordinary General Assembly was held in conjunction with the Ordinary General Assembly.
**An Extraordinary General Assembly held in conjunction with the Presidents’ Conference.
***An Extraordinary General Assembly was held on March 25 with statutes amendments as the only order of business.