International Mathematical Olympiad

The IMO has been held every year since 1959. It takes place in a different country (which is called the "host country") from year to year. However, it is often seen that this competition is dominated by the US and China.

	Venue	Year	Date	Top-ranked country[1]	Refs
1	Brașov and Bucharest	1959	July 21 – July 31	Romania	[2]
2	Sinaia	1960	July 18 – July 26	Czechoslovakia	[2]
3	Veszprém	1961	July 6 – July 16	Hungary	[2]
4	České Budějovice	1962	July 7 – July 15		[2]
5	Warsaw and Wrocław	1963	July 5 – July 13	Soviet Union	[2]
6	Moscow	1964	June 30 – July 10		[2]
7	East Berlin	1965	July 3 – July 13		[2]
8	Sofia	1966	July 1 – July 14		[2]
9	Cetinje	1967	July 2 – July 13		[2]
10	Moscow	1968	July 5 – July 18	East Germany	[2]
11	Bucharest	1969	July 5 – July 20	Hungary	[2]
12	Keszthely	1970	July 8 – July 22		[2]
13	Žilina	1971	July 10 – July 21		[2]
14	Toruń	1972	July 5 – July 17	Soviet Union	[2]
15	Moscow	1973	July 5 – July 16		[2]
16	Erfurt and East Berlin	1974	July 4 – July 17		[2]
17	Burgas and Sofia	1975	July 3 – July 16	Hungary	[2]
18	Lienz	1976	July 7 – July 21	Soviet Union	[2]
19	Belgrade	1977	July 1 – July 13	United States	[2]
20	Bucharest	1978	July 3 – July 10	Romania	[2]
21	London	1979	June 30 – July 9	Soviet Union	[2]
	The 1980 IMO was due to be held in Mongolia. It was cancelled, and split into two unofficial events in Europe.[3]
22	Washington, D.C.	1981	July 8 – July 20	United States	[2]
23	Budapest	1982	July 5 – July 14	West Germany	[2]
24	Paris	1983	July 1 – July 12		[2]
25	Prague	1984	June 29 – July 10	Soviet Union	[2]
26	Joutsa	1985	June 29 – July 11	Romania	[2]
27	Warsaw	1986	July 4 – July 15	Soviet Union  United States	[2]
28	Havana	1987	July 5 – July 16	Romania	[2]
29	Sydney and Canberra	1988	July 9 – July 21	Soviet Union	[2]
30	Braunschweig	1989	July 13 – July 24	China	[2]
31	Beijing	1990	July 8 – July 19		[2]
32	Sigtuna	1991	July 12 – July 23	Soviet Union	[2]
33	Moscow	1992	July 10 – July 21	China	[2]
34	Istanbul	1993	July 13 – July 24		[2]
35	Hong Kong	1994	July 8 – July 20	United States	[2]
36	Toronto	1995	July 13 – July 25	China	[4]
37	Mumbai	1996	July 5 – July 17	Romania	[5]
38	Mar del Plata	1997	July 18 – July 31	China	[6]
39	Taipei	1998	July 10 – July 21	Iran	[7]
40	Bucharest	1999	July 10 – July 22	China  Russia	[8]
41	Daejeon	2000	July 13 – July 25	China	[9]
42	Washington, D.C.	2001	July 1 – July 14		[10]
43	Glasgow	2002	July 19 – July 30		[11]
44	Tokyo	2003	July 7 – July 19	Bulgaria	[12]
45	Athens	2004	July 6 – July 18	China	[13]
46	Mérida	2005	July 8 – July 19		[14]
47	Ljubljana	2006	July 6 – July 18		[15]
48	Hanoi	2007	July 19 – July 31	Russia	[16]
49	Madrid	2008	July 10 – July 22	China	[17]
50	Bremen	2009	July 10 – July 22		[18]
51	Astana	2010	July 2 – July 14		[19]
52	Amsterdam	2011	July 12 – July 24		[20]
53	Mar del Plata	2012	July 4 – July 16	South Korea	[21]
54	Santa Marta	2013	July 18 – July 28	China	[22]
55	Cape Town	2014	July 3 – July 13		[23]
56	Chiang Mai	2015	July 4 – July 16	United States	[24]
57	Hong Kong	2016	July 6 – July 16		[25]
58	Rio de Janeiro	2017	July 12 – July 23	South Korea	[26]
59	Cluj-Napoca	2018	July 3 – July 14	United States	[27]
60	Bath	2019	July 11 – July 22	China  United States	[28]
61	Saint Petersburg	2020	September 19 – September 28	China	[29][30][31][32]
62	Saint Petersburg	2021	July 7 – July 17	China	[33]
63	Oslo	2022	July 6 – July 16		[34][35]
64	Chiba	2023	July 2 – July 13		[36]
65	Ukraine	2024			[37]
66	Melbourne	2025			[38]

The current ten countries with the best all-time results are as follows:[39]

Rank	Country	Appearances	Gold	Silver	Bronze	Honorable Mentions
1	China	36	168	36	6	0
2	United States	47	137	117	29	1
3	Russia	30	106	62	12	0
4	South Korea	34	86	74	28	7
5	Hungary	61	85	168	107	10
6	Romania	62	78	149	110	7
7	Soviet Union[n 1]	29	77	67	45	0
8	Vietnam	45	65	111	78	2
9	Bulgaria	62	55	123	114	13
10	Germany	44	53	105	83	16

Notes