King Frederick
King Frederick or King Frederik may refer to:
- Frederick I of Denmark
- Frederick II of Denmark
- Frederick III of Denmark
- Frederick IV of Denmark
- Frederick V of Denmark
- Frederick VI of Denmark
- Frederick VII of Denmark
- Frederik VIII of Denmark
- Frederik IX of Denmark
- Frederik X of Denmark
- Frederick I of Sweden
- Frederick I of Prussia, previously Frederick III, Elector of Brandenburg
- Frederick II of Prussia, Frederick the Great
- Frederick III, German Emperor, also King Frederick III of Prussia
- Frederick I of Württemberg
- Frederick of Naples
- Frederick I, Holy Roman Emperor, also King of Italy
- Frederick II, Holy Roman Emperor, also King Frederick I of Sicily
- Frederick III, Holy Roman Emperor, also King of Italy
- Frederick III of Sicily
- Frederick the Simple
- Frederick the Fair
- Frederick V of the Palatinate
- Frederick William I of Prussia
- Frederick William II of Prussia
- Frederick William III of Prussia
- Frederick William IV of Prussia
- Frederick Augustus I of Saxony
- Frederick Augustus II of Saxony
- Frederick Augustus III of Saxony