IY

IY may refer to:
* Imperial Yeomanry, British cavalry regiments (1899–1908)
* InuYasha, a long-running manga and anime series by Rumiko Takahashi
* Iraq-Saudi Arabian Neutral Zone: FIPS 10-4 digram; obsolete since 1993—although divided by treaty in 1981, this was never filed with the UN or any agency outside of the interested parties
* Ito-Yokado, a Japanese General Merchandise Store, which is a member of IY-Group
* Yemenia - Yemen Airways: IATA airline designator