• One of three emperors of ancient Rome and Byzantium:
• Theodosius I (347–395; "Theodosius the Great"), son of Count Theodosius
• Theodosius II (408–450)
• Theodosius III (715–717)

• One of three Pope of the Coptic Orthodox Church
• Pope Theodosius I of Alexandria
• Pope Theodosius II of Alexandria
• Pope Theodosius III of Alexandria

Others by the name are:

• Theodosius of Bithynia or Theodosius of Tripolis (c. 160 BC– c. 100 BC) was a Greek astronomer and mathematician.
• Theodosius the Cenobiarch (c. 423-529)
• Patriarch Theodosius I of Alexandria (535–567)
• Theodosius the Deacon, an unknown 10th century Byzantine poet who wrote the poem "The Conquest of Crete"
• Patriarch Theodosius II of Alexandria (c. 12th century)
• Theodosius of Kiev, 11th century Russian saint
• Theodosius, Metropolitan of Moscow (1461–1464)
• Metropolitan Theodosius (Lazor), former primate of the Orthodox Church in America (1933– )
• Theodosius Dobzhansky, noted geneticist and evolutionary biologist