// Workers AI · dad joke modeWhy did Frederick I go to the party? He was a first-class ruler.

Frederick I or Friedrich I may refer to:

• Frederick of Utrecht or Frederick I (815/16–834/38), Bishop of Utrecht.
• Frederick I, Duke of Upper Lorraine (942–978)
• Frederick I, Duke of Swabia (1050–1105)
• Frederick I, Count of Zollern (died 1125)
• Frederick I (archbishop of Cologne) (1075–1171)
• Frederick I, Holy Roman Emperor (1122–1190), "Frederick Barbarossa"
• Frederick I, Burgrave of Nuremberg (1139–1200)
• Frederick I, Duke of Lorraine (1143–1206)
• Frederick I, Count of Berg-Altena (1173–1198)
• Frederick I, Duke of Austria (Babenberg) (1175–1198), "Frederick the Catholic"
• Frederick I, Margrave of Baden (1249–1268)
• Frederick I, Margrave of Meissen (1257–1323), "the Brave"
• Frederick I of Austria (Habsburg) (1286–1330), "Frederick the Fair"
• Frederick I, Marquess of Saluzzo (1287–1336)
• Frederick I, Count of Celje (1300-59)
• Frederick I, Duke of Athens (died 1355)
• Frederick I, Elector of Saxony (1370–1428), "the Belligerent" or "the Warlike"
• Frederick I, Elector of Brandenburg (1371–1440), also Burgrave of Nuremberg (as Frederick VI)
• Frederick I, Count of Vaudémont (1371–1415)
• Frederick I, Duke of Brunswick-Lüneburg (died 1400)
• Frederick I, Count Palatine of Simmern (1417–1480), "the Hunsrücker"
• Frederick I, Duke of Brunswick-Osterode (died 1421)
• Frederick I, Elector Palatine (1425–1476), "the Victorious"
• Frederick I of Mantua (1441–1484), Marquess of Mantua
• Frederick I of Naples (1452–1504), King of Naples
• Frederick I, Margrave of Brandenburg-Ansbach (1460–1536)
• Frederick I of Denmark (1471–1533), King of Denmark and Norway
• Frederick I, Duke of Württemberg (1557–1608)
• Frederick I, Landgrave of Hesse-Homburg (1585–1638)
• Frederick I, Duke of Saxe-Gotha-Altenburg (1646–1691)
• Frederick I of Prussia (1657–1713), King in Prussia
• Frederick I of Sweden (1676–1751), King of Sweden
• Frederick I of Württemberg (1754–1816), King of Württemberg
• Frederick I, Duke of Saxe-Altenburg (1763–1834)
• Frederick I, Grand Duke of Baden (1826–1907)
• Frederick I, Duke of Anhalt (1831–1904)

See also

• Frederik I (disambiguation)
• Frederick William I (disambiguation)
• Frederick Augustus I, Elector of Saxony (1670–1733), better known as King August II of Poland
• Frederick Augustus I of Saxony (1750–1827), king of Saxony 1806–1827
• Frederick Augustus I, Duke of Oldenburg (1711–1785)
• Frederick Christian I, Duke of Schleswig-Holstein-Sonderburg-Augustenburg (1721–1794)
• Frederick Francis I, Grand Duke of Mecklenburg-Schwerin (1756–1837)
• Frederick Magnus I, Count of Solms-Laubach (1521–1561)