Saint Irene may refer to:
- Irene of Thessalonica, one of three virgin sisters killed in 304, feast day April 3
- Irene of Rome (died c. 288), wife of martyr Saint Castulus, feast day January 22
- Irene of Tomar (died c. 653), of Portugal, feast day October 20
- Irene of Macedonia [ru] (died in 2nd century or 315), considered great-martyr with feast day May 5 (Eastern Orthodox liturgics) in Eastern Orthodox churches
- Irene of Cappadocia, abbess, feast day July 28 (Eastern Orthodox liturgics) in Eastern Orthodox churches
- Irene of Hungary, empress (died 1134), feast day August 13 in Eastern Orthodox churches
- Hagia Irene church in Istanbul is often called "St Irene", although it is actually named after the "Holy (Divine) Peace"