Supreme Headquarters is used by some nations and alliances to refer to the physical location of their high command.
Europe Supreme Headquarters (Yugoslav Partisans), the headquarters of the Communist Yugoslavian Partisans Supreme Headquarters Allied Expeditionary Force, the headquarters of the Commander of Allied forces in north-west Europe Supreme Headquarters Allied Powers Europe, the headquarters of the North Atlantic Treaty Organization Supreme Commander's Headquarters (India and Pakistan), transitional British military authority during the partition of India
Fiction Supreme Headquarters, International Espionage and Law-Enforcement Division (S.H.I.E.L.D), in Marvel Comics