The International Olympiad on Astronomy and Astrophysics (IOAA) is one of the twelve International Science Olympiads. Founded by five countries (Thailand, Indonesia, Iran, China, and Poland), its first edition took place in Thailand in 2007. The competition aims to foster interest in astronomy and astrophysics among young people from participating countries, as well as to strengthen ties between different nations and promote the exchange of scientific and cultural knowledge and experiences.

IOAA 2025 will take place in Mumbai, India.