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 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 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.

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

Past International Olympiad in Informatics'

• 1989 - Pravetz, Bulgaria - May 16-19
• 1990 - Minsk, Belarussian Republic, 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 - November/December 30-7
• 1998 - Setúbal, Portugal - September 5-12
• 1999 - Antalya-Belek, Turkey - 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