Thomas I

• Thomas I of Constantinople, Patriarch from 607 to 610
• Thomas I of Jerusalem, Patriarch until 821
• Thomas I of York
• Thomas I, Count of Savoy
• Thomas I d'Autremencourt, Lord of Salona
• Thomas I of Esztergom
• Thomas I of Saluzzo
• Thomas I Komnenos Doukas
• Baselios Thomas I