The idea of initiating international olympiads in informatics for school students was proposed to the 24th General Conference of the United Nations Educational, Scientific and Cultural Organization (UNESCO) in Paris by the Bulgarian delegate Professor Blagovest Sendov in October 1987. This plan was included into the Fifth Main Program of UNESCO for the biennium 1988-1989 (Section 05 215).

In May 1989, UNESCO initiated and sponsored the first International Olympiad in Informatics (IOI). (Quoted from the IOI'89 and IOI'92 Report). The first IOI was held in Bulgaria in 1989.

The IOI is organized annually in and by one of the participating countries. Each participating country typically sends a delegation of four contestants and two accompanying adults. Students compete individually and try to maximize their score by solving a set of informatics problems during two competition days. Cultural and recreational events are organized on the remaining days.

The competition tasks are of algorithmic nature; however, the contestants have to show such basic IT skills as problem analysis, design of algorithms and data structures, programming and testing. The winners of the IOI belong to the best young computer scientists in the world.

Locations of past and future IOI's include:
   Please note that each link contains problems, test cases and/or solutions.

1989	Pravetz, Bulgaria	May 16-19
1990	Minsk, Soviet Union	July 15-21
1991	Athens, Greece	May 19-25
1992	Bonn, Germany	July 11-21
1993	Mendoza, Argentina	October 16-25
1994	Haninge, Sweden	July 3-10
1995	Eindhoven, The Netherlands	June/July 26-3
1996	Veszprém, Hungary	July/August 25-2
1997	Cape Town, South Africa	Nov/Dec 30-7
1998	Setúbal, Portugal	September 5-12
1999	Antalya-Belek, Türkiye	October 9-16
2000	Beijing, China	September 23-30
2001	Tampere, Finland	July 14-21
2002	Yong-In, Korean Republic	August 18-25
2003	Kenosha, Wisconsin, USA	August 16-23
2004	Athens, Greece	September 11-18
2005	Nowy Sacz, Poland	August 18-25
2006	Mérida, Yucatán, Mexico	August 13-20
2007	Zagreb, Croatia	August 15-22
2008	Cairo, Egypt	August 16-23
2009	Plovdiv, Bulgaria	August 8-15
2010	Waterloo, Ontario, Canada	August 14-21
2011	Pattaya, Thailand	July 22-29
2012	Sirmione, Italy	September 23-30
2013	Brisbane, Australia	July 6-13
2014	Taipei, Taiwan	July 13-20
2015	Almaty, Kazakhstan	July/August 26-2
2016	Kazan, Russian Federation	August 12-19
2017	Tehran, Iran	July/August 28-4
2018	Tsukuba, Japan	September 1-8
2019	Baku, Azerbaijan	August 4-11
2020	Online* (Singapore)	September 13-19
2021	Online* (Singapore)	June 19-25
2022	Yogyakarta, Indonesia	August 7-15
2023	Szeged, Hungary	August/September 28-4

Future contests:

The IOI is one of five international science olympiads. The primary goal of the IOI is to stimulate interest in informatics (computing science) and information technology. Another important goal is to bring together exceptionally talented pupils from various countries and to have them share scientific and cultural experiences.