The IAU Office for Astronomy Outreach (IAU OAO) bridges the International Astronomical Union (IAU) with the global astronomy community of amateur astronomers, outreach practitioners, educators, communicators, and the general public. The office manages a number of programmes through international collaboration to make the science of astronomy accessible to all.

The IAU OAO is a joint project of the IAU and the National Astronomical Observatory of Japan (NAOJ). The IAU OAO is located on the NAOJ Mitaka Campus in Mitaka, Japan.