IU

IU may mean:

*Indiana University (most often the flagship campus in Bloomington)
*a misnomer for IUP, Indiana University of Pennsylvania
*Intermediate Unit, a regional educational service agency in Pennsylvania
*International unit, a unit for biological activity used in pharmacology
*International University, Cambodia, private higher education institution in Phnom Penh, Cambodia
*International University in Germany, a university in Southern Germany
*Instrument Unit, a guidance system for the Saturn V rocket
*Inuktitut language (ISO 639 alpha-2)
*Istanbul University
*"Izquierda Unida" ("United Left" in Spanish, political party):
**Izquierda Unida (Argentina)
**Izquierda Unida (Spain)

Iu may refer to:
* the "Iu interface", which links the RNC to either a MSC or a SGSN in a UMTS network.