HY or Hy may refer to:
- Hy, a Lisp dialect for Python
- HY (band), a Japanese band
- Hy (island), a pre-Christian and early Christian name for the Scottish island Iona
- Hy (name), a given name, nickname, or surname
- HY (satellite), a series of Chinese marine remote sensing satellites
Other uses
- hy, the ISO 639-1 language code for the Armenian language
- HY, the IATA code for Uzbekistan Airways, the national airline of Uzbekistan
- H-Y antigen, a male tissue specific antigen
- HY Velorum, a binary star system
- HY-80, a type of alloy steel
- HY-124798, a chemistry compound
- Hy-V, a flight experiment research project
- HY1935 bayonet, a Chinese infantry weapon