The title chief of staff (or head of staff) identifies the leader of a complex organization such as the armed forces, institution, or body of persons and it also may identify a principal staff officer (PSO), who is the coordinator of the supporting staff or a primary aide-de-camp to an important individual, such as a president, or a senior military officer, or leader of a large organization.^[1][2]

In general, a chief of staff provides a buffer between a chief executive and that executive's direct-reporting team. The chief of staff generally works behind the scenes to solve problems, mediate disputes, and deal with issues before they are brought to the chief executive.^[1] Often chiefs of staff act as a confidant and advisor to the chief executive, acting as a sounding board for ideas. Ultimately the actual duties depend on the position and the people involved.^[1]

• Chief of Staff to the Prime Minister

• Chief of Staff of the Presidency

• Chief of Staff to the Prime Minister
• Principal Secretary

• Chief of Staff of the Presidency

• Head of the German Chancellery

• Principal Secretary to the Prime Minister of India

• Chief of Staff to the President

• Principal Secretary to the President
• Principal Secretary to the Prime Minister

• Chief of Staff (Philippines), a former position in the Cabinet of the Philippines, serving under the President of the Philippines
• Special Assistant to the President

• Chief Presidential Secretary, chief of staff to the President of South Korea

• Moncloa Chief of Staff

• Private Secretary to the Sovereign
• Downing Street Chief of Staff
• Cabinet Secretary
• Principal Private Secretary to the Prime Minister
• Principal Private Secretary to the Secretary of State for Foreign and Commonwealth Affairs

• Chief of Staff to the First Minister

• Chief of staff, the most senior staff member in the office of a member of the United States Congress
• White House Chief of Staff^[2]

In general, the positions listed below are not "chiefs of staff" as defined at the top of this page; they are the heads of the various forces/commands and tend to have subordinates that fulfill the "chief of staff" roles.^{[citation needed]}

• Chief of the Defence
• Chief of the Defence Staff
• Chief of the General Staff
• Chief of the Army Staff
• Chief of the Air Staff
• Chief of the Naval Staff
• Category:Vice chiefs of staff

• Chief of General Staff of Azerbaijani Armed Forces - head of General Staff of Azerbaijani Armed Forces

• Chief of the Defence Staff (Canada)
  • Chief of the General Staff
  • Chief of the Naval Staff
  • Chief of the Air Staff

• Chief of the Defence Staff (French: Chef d'État-Major des Armées, CEMA)
  • Chief of Staff of the French Air Force (French: Chef d'État-Major de l'Armée de l'Air, CEMAA)
  • Chief of Staff of the French Army (French: Chef d'État-Major de l'Armée de Terre, CEMAT)
  • Chief of Staff of the French Navy (French: Chef d'État-Major de la Marine, CEMM)
  • Chief of Staff of the French Gendarmerie (French: Directeur-Général de la Gendarmerie, DGGN)

• Chief of Defence Staff
  • Chief of the Army Staff
  • Chief of the Navy Staff
  • Chief of the Air Staff

• Chief of the Defence Staff (Greece)
  • Chief of Staff of the Hellenic Air Force
  • Chief of Staff of the Hellenic Army
  • Chief of Staff of the Hellenic Navy

• Chief of Defence Staff (Indian Armed Forces)
  • Chief of the Army Staff (Indian Army)
  • Chief of the Naval Staff (Indian Navy)
  • Chief of the Air Staff (Indian Air Force)

• Chief of Staff of the Indonesian Army
• Chief of Staff of the Indonesian Navy
• Chief of Staff of the Indonesian Air Force

• Chief of Staff of the Defence Forces

• Chief of the Israeli General Staff

• Chief of the Defence Staff
  • Chief of the Army Staff
  • Chief of the Navy Staff
  • Chief of the Air Force Staff

• Chairman Joint Chiefs of Staff Committee
  • Chief of Army Staff
    • CGS
  • Chief of Naval Staff
    • Vice Chief of the Naval Staff
  • Chief of Air Staff (Pakistan)

• Chief of Staff, Armed Forces of the Philippines, later renamed to the Chairman of the Joint Chiefs, AFP - exercises command and control over all elements of the Armed Forces of the Philippines.

• Chief of the General Staff of the Armed Forces (Portuguese: Chefe do Estado-Maior-General das Forças Armadas, CEMGFA) - operational commander of the Portuguese Armed Forces
  • Chief of Staff of the Navy (Portuguese: Chefe do Estado-Maior da Armada, CEMA) - commander of the Portuguese Navy
  • Chief of Staff of the Army (Portuguese: Chefe do Estado-Maior do Exército, CEME) - commander of the Portuguese Army
  • Chief of Staff of the Air Force (Portuguese: Chefe do Estado-Maior da Força Aérea, CEMFA) - commander of the Portuguese Air Force

• Chief of the Defence Staff
  • Chief of Staff of the Army
  • Chief of Staff of the Navy
  • Chief of Staff of the Air Force

• Chief of the Defence Staff (Sri Lanka) - the most senior appointment in the Sri Lankan Armed Forces.
  • Chief of Staff of the Army - deputy commander of the Sri Lankan Army
  • Chief of Staff of the Navy - deputy commander of the Sri Lankan Navy
  • Chief of Staff of the Air Force - deputy commander of the Sri Lankan Air Force

• Chief of the Defence Staff (CDS) - the professional head of the British Armed Forces.
  • Chief of the Naval Staff, more commonly called the First Sea Lord
  • Chief of the General Staff, formerly the Chief of the Imperial General Staff
  • Chief of the Air Staff

The Sovereign is the Commander-in-Chief. The CDS heads the Chiefs of Staff Committee and is assisted by the Vice-Chief of the Defence Staff.

• Joint Chiefs of Staff, headed by the Chairman of the Joint Chiefs of Staff (CJCS)
  • Chief of Staff of the United States Army
    • An Army general (O-10) serving as the senior ranking officer within the United States Army, but subordinate to any Army O-10 serving as CJCS or Vice CJCS
  • Chief of Staff of the United States Air Force
    • An Air Force general (O-10) serving as the senior ranking officer within the United States Air Force, but subordinate to any USAF O-10 serving as CJCS or Vice CJCS
• In unified combatant commands, headed by a general (O-10) or Navy admiral (O-10)
  • A major general (O-8) or Navy or Coast Guard rear admiral (O-8) overseeing the command's directorates
• In military commands headed by a lieutenant general (O-9), vice admiral (O-9), major general (O-8) or rear admiral (O-8), or brigadier general (O-7) or rear admiral, lower half (O-7)
  • A colonel (O-6) or Navy or Coast Guard captain (O-6) overseeing the entire general officer's/flag officer's command staff; in some cases may also be referred to as an executive assistant or executive officer
    • In some commands and organizations, two officers in pay grade O-6 may be assigned as chief of staff and executive assistant, respectively.

• Chief of Defence
• Chief Secretary (disambiguation)
• General secretary
• Permanent secretary
• Principal Private Secretary
• Provincial secretary

• Media related to Chiefs of staff at Wikimedia Commons