Chief of staff

The title, Chief of Staff, identifies the leader of a complex organization, 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.

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 bubble up to the Chief Executive. Often Chiefs of Staff act as a confidante and advisor to the Chief Executive, acting as a sounding board for ideas. Ultimately the actual duties depend on the actual position and the people involved.

Medicine

 * The chief of staff in a hospital is the primary leader of all divisions and staff, including divisions that have chiefs as well, such as, leadership over chief of surgery, chief of obstetrics, chief of orthopedics, etc. as divisions that each are headed by a leader in that specialty. The chief of staff is inevitably a physician, as opposed to the chief administrator, who is often a non-medical professional.

Government

 * Chief of Staff to the President of Brazil
 * Chief of Staff to the Prime Minister (Canada)
 * Chief of Staff (Philippines), a former position in the Cabinet of the Philippines, serving under the President of the Philippines
 * Downing Street Chief of Staff (United Kingdom)
 * White House Chief of Staff (United States)
 * Chief of Staff to the Vice President of the United States
 * Chief of staff (United States Congress), the most senior staff member in the office of a member of the United States Congress
 * Principal Staff Officer to the Prime Minister (Pakistan)

Military
In general, the positions listed below are not "chiefs of staff" as defined at the top of this page. In general, they are the heads of the various forces/commands. Note that, in general, they tend to have subordinates that do fulfill the "chief of staff" roles.

In general

 * Chief of the Defence Force
 * 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

In Australia

 * Chief of the Defence Force - the professional head of the Australian Defence Force
 * Chief of Navy (Australia)
 * Chief of Army (Australia)
 * Chief of Air Force (Australia)

In Azerbaijan

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

In Canada

 * Chief of the Defence Staff (Canada)
 * Chief of the Air Staff (Canada)

In France

 * 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)

In Ghana

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

In Ireland

 * Irish Defence Forces Chief of Staff

In Italy

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

In Pakistan

 * Joint Chiefs of Staff Committee, headed by the Chairman Joint Chiefs of Staff Committee
 * Chief of Army Staff
 * Chief of Air Staff
 * Chief of Naval Staff
 * Commandant of Pakistan Marines
 * Commandant of Pakistan Coast Guard

In the Philippines

 * Chief of Staff, Armed Forces of the Philippines - exercises command and control over all elements of the Armed Forces of the Philippines

In the United Kingdom
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. The Queen is not the ceremonial head of each branch of the British Armed Forces.
 * Chief of the Defence Staff (United Kingdom) - 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

In the United States

 * Joint Chiefs of Staff, headed by the Chairman of the Joint Chiefs of Staff
 * Chief of Staff of the United States Army
 * Commandant of the Marine Corps
 * Chief of Naval Operations
 * Chief of Staff of the United States Air Force
 * Chief of the National Guard Bureau

In former states

 * Chef des Stabes, commander of the Nazi Sturmabteilung