Ijo may refer to:
- Ijo Temple, a 10th-century Hindu temple in Yogyakarta, Indonesia
- A subgroup of the Ijaw people of Nigeria, Africa
- Ijoid languages (or Ịjọ), spoken by the Ijo people
- Southeast Ijo, an Ijaw language
- Ii, Finland (), a municipality in Finland
As an acronym
- Islamic Jihad Organization
- International Journal of Obesity