Frederick I was the name of several European monarchs:
- Frederick Barbarossa, Holy Roman Emperor (1122-1190)
- Frederick I Babenberg, Duke of Austria (c.1175-1198])
- Frederick I Habsburg (Frederick the Handsome), Duke of Austria, (1286-1330)
- Frederick I, King of Denmark and Norway (1471-1533)
- Frederick Wilhelm I, Great Elector of Brandenburg, Duke of Prussia (1620-1688)
- Frederick I, King in Prussia, (1657-1713)
- Frederick Wilhelm I, King of Prussia, (1688-1740)
- Frederick Augustus I, King of Saxony, Duke of Warsaw (1750-1827)
- Frederick I, King of Württemberg (1754-1816)
