Before he was crowned King, his royal title was: Sdech Krom Khun (Khmer: ស្តេចក្រុមឃុន), equating him to the rank of Great Prince.
As King, his title is: Preah Karuna Preah Bat Sâmdach Preah Bâromneath Norodom Sihamoni Preah Mohaksat Nai Preah Reacheanachak Kampuchea (in romanized Khmer); roughly translating to: His Majesty, King Norodom Sihamoni of the Kingdom of Cambodia. His given name, Sihamoni, comprises two morphemes from his parent's given names, Sihanouk and Monineath.