A Jain is a follower of Jainism, a religion of India.
Jain or JAIN may also refer to:
- Jain (singer) (born 1992), French singer-songwriter
- Jain (surname), a surname and list of notable people with the surname
- Jain, Iran, a village in Hormozgan Province, Iran
- Java APIs for Integrated Networks
- Jain Irrigation Systems
- Jain, a fictional race in Neal Asher's Polity series of science fiction novels