Aira is a genus of Old World plants.
Aira or 姶良 may also refer to:
- Aira, Kagoshima, a city in Japan
- Aira, Kagoshima (Aira District), a former town in the Aira District, Kagoshima, Japan
- Aira, Kagoshima (Kimotsuki District), a former town in the Kimotsuki District, Kagoshima, Japan
- Aira District, Kagoshima, a district in Japan
- Aira Caldera, a caldera in Japan
- Aira Force, a waterfall in the Lake District, United Kingdom