Theodore I
Theodore I may refer to:
- Patriarch Theodore I of Alexandria, Greek Patriarch of Alexandria
- Pope Theodore I
- Theodore I Calliopas, Exarch of Ravenna
- Patriarch Theodore I of Constantinople
- Theodore I Laskaris, Emperor of Nicaea
- Teodor I Muzaka, Albanian despot
- Theodore I Palaiologos, Despot of the Morea in 1383-1407
- Tewodros I of Ethiopia, Emperor of Ethiopia, sometimes known as Theodore I
- Feodor I of Russia, Tsar of Russia, 1584–1598
- Theodore I of Corsica, King of Corsica