The Chief of the Defence Staff (Spanish: Jefe del Estado Mayor de la Defensa, JEMAD) is the highest-ranking military officer in the Spanish Armed Forces and is the principal military advisor to the Prime Minister, the Minister of Defence, the National Defence Council and the National Security Council.

The JEMAD has three different roles: the support role, assisting and advising the Prime Minister and the Minister of Defence in military affairs and supports the Under Secretary of Defence in its duties over the military personnel; the strategic role, being the official in charge of design the military strategy, directs the military operations and the actions to guarantee cyberspace freedom (with the supervision of the Minister), assign the military forces for the missions and give orders to the other Chiefs of Staff to appoint new commanders; and the preparatory role, coordinating the Chiefs of Staff and giving orders to them to prepare the troops, oversees the internal organization of the different branches, establish the common rules and regulations of the Armed Forces, ensures compliance with military discipline, staff motivation and their well-being and establish the organization of the Armed Forces (in coordination with the others Chiefs of Staff).

[3] On June 9, 1810 is constituted for the first time in Spain the Body of General Staff, separated completely from the other Armies branches, following their top officials different military careers.

Once the War of Independence was over, by Royal Order of June 27, 1814, Ferdinand VII suppressed the General Staff Body.

The High Command was active throughout Francoist Spain and part of the Spanish transition to democracy, disappearing on June 13, 1980.