International Mathematical Olympiad

Timeline

#	Year	Country	City	Date	Countries	Contestants
#	Year	Country	City	Date	Countries	All	M	F
13	1971	Czechoslovakia	Žilina	10.7. - 21.7.	15	115	98	4
5	1963	Poland	Wrocław	5.7. - 13.7.	8	64	53	2
42	2001	United States of America	Washington	1.7. - 14.7.	83	473	440	33
22	1981	United States of America	Washington	8.7. - 20.7.	27	185	155	9
27	1986	Poland	Warsaw	4.7. - 15.7.	37	210	147	7
3	1961	Hungary	Veszprém	6.7. - 16.7.	6	48	34	5
14	1972	Poland	Toruń	5.7. - 17.7.	14	107	90	2
36	1995	Canada	Toronto	13.7. - 25.7.	73	412	305	27
44	2003	Japan	Tokyo	7.7. - 19.7.	82	457	333	29
68	2027	Hungary	TBA
66	2025	Australia	TBA
39	1998	Taiwan	Taipeh	10.7. - 21.7.	76	419	298	30
41	2000	Republic of Korea	Taejon	13.7. - 25.7.	82	461	337	31
8	1966	Bulgaria	Sofia	1.7. - 14.7.	9	72	59	1
2	1960	Romania	Sinaia	18.7. - 26.7.	5	39	32	1
32	1991	Sweden	Sigtuna	12.7. - 23.7.	56	318	277	17
67	2026	People's Republic of China	Shanghai
54	2013	Colombia	Santa Marta	18.7. - 28.7.	97	527	475	52
58	2017	Brazil	Rio de Janeiro	12.7. - 23.7.	111	615	553	62
25	1984	Czechoslovakia	Prague	29.6. - 10.7.	34	192	132	3
24	1983	France	Paris	1.7. - 12.7.	32	186	178	8
63	2022	Norway	Oslo	6.7. - 16.7.	104	589	521	68
37	1996	India	Mumbai	5.7. - 17.7.	75	424	314	25
33	1992	Russian Federation	Moscow	10.7. - 21.7.	56	322	271	14
6	1964	Union of Soviet Socialist Republics	Moscow	30.6. - 10.7.	9	72	54	4
15	1973	Union of Soviet Socialist Republics	Moscow	5.7. - 16.7.	16	125	115	2
10	1968	Union of Soviet Socialist Republics	Moscow	5.7. - 18.7.	12	96	88
46	2005	Mexico	Mérida	8.7. - 19.7.	91	513	469	43
38	1997	Argentina	Mar del Plata	18.7. - 31.7.	82	460	318	28
53	2012	Argentina	Mar del Plata	4.7. - 16.7.	100	547	496	51
49	2008	Spain	Madrid	10.7. - 22.7.	97	535	480	55
21	1979	United Kingdom	London	30.6. - 9.7.	23	166	116	1
47	2006	Slovenia	Ljubljana	6.7. - 18.7.	90	498	460	38
18	1976	Austria	Lienz	7.7. - 21.7.	18	139	117	4
12	1970	Hungary	Keszthely	8.7. - 22.7.	14	112	94	5
26	1985	Finland	Joutsa	29.6. - 11.7.	38	209	151	7
34	1993	Türkiye	Istanbul	13.7. - 24.7.	73	413	297	34
35	1994	Hong Kong	Hong Kong	8.7. - 20.7.	69	385	284	26
57	2016	Hong Kong	Hong Kong	6.7. - 16.7.	109	602	531	71
28	1987	Cuba	Havanna	5.7. - 16.7.	42	237	160	7
48	2007	Vietnam	Hanoi	19.7. - 31.7.	93	520	471	49
43	2002	United Kingdom	Glasgow	19.7. - 30.7.	84	479	341	37
16	1974	German Democratic Republic	Erfurt	4.7. - 17.7.	18	140	124	2
59	2018	Romania	Cluj-Napoca	3.7. - 14.7.	107	594	535	59
64	2023	Japan	Chiba	2.7. - 13.7.	112	618	550	67
56	2015	Thailand	Chiang Mai	4.7. - 16.7.	104	577	525	52
9	1967	Yugoslavia	Cetinje	2.7. - 13.7.	13	99	82	1
4	1962	Czechoslovakia	České Budějovice	7.7. - 15.7.	7	56	48	4
55	2014	South Africa	Cape Town	3.7. - 13.7.	101	560	504	56
29	1988	Australia	Canberra	9.7. - 21.7.	49	268	251	17
17	1975	Bulgaria	Burgas	3.7. - 16.7.	17	135	99	2
23	1982	Hungary	Budapest	5.7. - 14.7.	30	119	87	3
40	1999	Romania	Bucharest	10.7. - 22.7.	81	450	319	37
11	1969	Romania	Bucharest	5.7. - 20.7.	14	112	95	6
20	1978	Romania	Bucharest	3.7. - 10.7.	17	132	112	3
50	2009	Germany	Bremen	10.7. - 22.7.	104	565	506	59
30	1989	Germany	Braunschweig	13.7. - 24.7.	50	291	212	13
1	1959	Romania	Braşov	21.7. - 31.7.	7	52	41	6
7	1965	German Democratic Republic	Berlin	3.7. - 13.7.	10	80	63	9
19	1977	Yugoslavia	Belgrade	1.7. - 13.7.	21	155	132	2
31	1990	People's Republic of China	Beijing	8.7. - 19.7.	54	308	238	12
60	2019	United Kingdom	Bath	11.7. - 22.7.	112	621	556	65
65	2024	United Kingdom	Bath	11.7. - 22.7.
45	2004	Greece	Athens	6.7. - 18.7.	85	486	351	37
51	2010	Kazakhstan	Astana	2.7. - 14.7.	95	522	469	47
52	2011	Netherlands	Amsterdam	12.7. - 24.7.	101	563	506	57
62	2021	Russian Federation	A distributed IMO administered from St Petersburg	14.7. - 24.7.	107	619	555	64
61	2020	Russian Federation	A distributed IMO administered from St Petersburg	19.9. - 28.9.	105	616	560	56

Gender of some contestants is not known. Please send relevant information to the webmaster: webmaster@imo-official.org.