IPAC may refer to:
- OPAC, Online Public Access Catalog, this in an older term which is now quite often replaced with the term iPAC
- Infrared Processing and Analysis Center, the NASA science center which is responsible for the data processing, analysis, and archiving for NASA's infrared astronomy and astrophysics missions
- International Plus, Advanced & Challenge Square Dance Convention, an international square dance event that has taken place every two years in Barmstedt, Germany since 1993
- Iraq Peace Action Coalition, an antiwar organization based in Minneapolis, Minnesota