Orthodox Church may refer to:
- Eastern Orthodox Church, the second-largest Christian church
- Oriental Orthodox Churches, a branch of Eastern Christianity
- Orthodox Presbyterian Church, a confessional Presbyterian denomination located primarily in the United States
- Orthodox Presbyterian Church of New Zealand, a denomination formed in the 1960s led by George Mackenzie
- State church of the Roman Empire, Roman Empire's state religion after 380 CE
- True Orthodox church, a movement within Eastern Orthodox Christianity
See also
- Eastern Orthodoxy
- Eastern Christianity
- Neo-orthodoxy
- Catholic Church (disambiguation)
- Orthodox (disambiguation)
- Orthodox calendar (disambiguation)
- Orthodox Communion (disambiguation)
- Orthodoxy by country (disambiguation)
- Orthodox Catholic Church (disambiguation)
- Greek Orthodox Church (disambiguation)