thumb|[[Joint Chiefs of Staff of the U.S. Department of Defense in 2024]]

Chief of staff (or head of staff) is a leadership title with different meanings in civilian and military organizations. In civilian government organizations and businesses, a chief of staff is a primary aide-de-camp to an important individual, such as a president or leader of a large organization. In military organizations, a chief of staff is the leader of a complex organization, such as one of a country's armed forces, while the role that coordinates supporting staff for a senior military officer may be titled a principal staff officer (PSO).

Civilian

thumb|[[White House Chief of Staff, Susie Wiles, with President Donald Trump in 2025]]

In civilian organizations, 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. as an integrator connecting work streams that would otherwise remain siloed; as a communicator linking the leadership team and the broader organization; as an honest broker and truth teller when the leader needs a wide-ranging view; and as a confidant without an organizational agenda. An organization may also hire an associate chief of staff (ACoS), a senior operational role that serves as a partner to the chief of staff (CoS).

Government

Australia

  • Chief of Staff to the Prime Minister

Brazil

  • Chief of Staff of the Presidency

Canada

  • Chief of Staff to the Prime Minister
  • Principal Secretary

Colombia

  • Chief of Staff of the Presidency

France

In France, a distinction is made between a politician's directeur de cabinet and chef de cabinet. The directeur de cabinet is tasked with organising the work of the staff and is authorised to make certain decisions or speak on behalf of the politician. It is thus the more political role. The chef de cabinet is under the authority of the directeur de cabinet and is tasked with organising the politician's agenda.

At the Élysée, a third function exists: the Secrétaire général de la présidence de la République (Secretary-General of the Presidency of the Republic). The officeholder is the de facto chief of staff to the President of France, above the directeur de cabinet and chef de cabinet. The secretary-general is the president's closest advisor, coordinating with the government and taking part in the weekly Council of Ministers.

Germany

  • Head of the German Chancellery

India

  • Principal Secretary to the Prime Minister of India

Nigeria

  • Chief of Staff to the President

Pakistan

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

Philippines

  • 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

South Korea

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

Spain

  • Moncloa Chief of Staff

United Kingdom

  • 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
Scotland
  • Chief of Staff to the First Minister

United States

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