國際數學奧林匹克（IMO）是世界性的高中生數學比賽，每年於不同國家或地區舉行。首屆 IMO 於 1959 年在羅馬尼亞舉行，共有 7 個東歐國家參賽。歷年來，賽事逐漸成為一項重要國際盛事，吸引超過 100 個國家及地區參加。香港於 1988 年首次參加。每個國家或地區的代表隊包括一名領隊，一名副領隊及 6 名未進入大學的學生。
IMO 的宗旨為：
為世界各地年青數學精英提供接觸機會；
提升學生對數學的興趣；
促進教師間就數學教育的交流；及
及為各國學生及教師建立友誼，以促進國際間互相瞭解。
國際數學奧林匹克香港委員會（委員會）於 1986 年由岑嘉評教授領導成立，為具潛質的學生提供培訓課程，並透過多輪選拔，挑選香港代表隊成員參加 IMO。委員會也選拔學生參加其他數學比賽，包括中國數學奧林匹克（CMO）和中國女子數學奧林匹克（CGMO）。委員會曾於 1994 年及 2016 年在香港主辦 IMO。
The International Mathematical Olympiad (IMO) is the world championship mathematics competition for high school (pre-university) students and is held annually in a different country or region. The IMO first came into being in 1959 in Romania, involving 7 countries in Eastern Europe; gradually it has become an important world class event with more than 100 participating countries and regions. Hong Kong has joined the IMO since 1988. Each team comprises a Leader, a Deputy Leader and 6 students at pre-university level.
The goals of the IMO are:
to provide a meeting place for mathematically talented young people from all over the world;
to promote among students an interest in mathematics;
to promote among teachers an exchange of ideas on the development of math education; and
to establish personal and friendly contacts among students and teachers as a means of contribution to international understanding.
Founded in 1986 under the auspices of Prof KP Shum, the International Mathematical Olympiad Hong Kong Committee (IMOHKC) provides training to talented students and selects Hong Kong team members for the IMO via a series of tests. The IMOHKC also selects the Hong Kong team for other mathematics contests, including the Chinese Mathematical Olympiad (CMO) and the China Girls Mathematical Olympiad (CGMO). The IMOHKC has hosted the IMO in Hong Kong in 1994 and 2016.