Ulrich I may refer to:
Ulrich I, Duke of Brno (died 1113) Ulrich I, Bishop of Passau (c. 1027–1121) Ulrich I, Duke of Carinthia (died 1144) Ulrich I, Count of Württemberg (1226–1265) Ulrich I, Lord of Hanau (c. 1255/1260 – 1305/1306) Ulrich I, Count of Celje (1331-1368) Ulrich I, Duke of Mecklenburg-Stargard (before 1382–1417) Ulrich I, Count of East Frisia (1408–1466) Ulrich I, Duke of Württemberg (1487–1550)