Thomas I

Thomas I may refer to:


 * Thomas I of Constantinople, Patriarch from 607 to 610
 * Thomas I of Jerusalem, Patriarch until 821
 * Thomas I of York (died in 1100)
 * Thomas I, Count of Savoy (1178–1233)
 * Thomas I d'Autremencourt (died ca. 1212), Lord of Salona
 * Thomas I, Archbishop of Esztergom (1224)
 * Thomas I of Saluzzo (died in 1296)
 * Thomas I Komnenos Doukas (c. 1285–1318)
 * Baselios Thomas I (1929– )