The Secretariat, one of the main organs of the UN, is organized along departmental lines, with each department or office having a distinct area of action and responsibility. Offices and departments coordinate with each other to ensure cohesion as they carry out the day to day work of the Organization in offices and duty stations around the world.  At the head of the United Nations Secretariat is the Secretary-General.

A view of the Secretariat Building, with Members States’ flags flying in the foreground, at United Nations headquarters in New York.


The Secretary-General is the chief administrative officer and head of the Secretariat.

Offices and Departments at Headquarters in New York

Executive Office of the Secretary-General
Office of Internal Oversight Services
Office of Legal Affairs
Department of Political and Peacebuilding Affairs
Office for Disarmament Affairs
  • Weapons of Mass Destruction Branch
  • Conventional Arms Branch
  • Information and Outreach Branch
  • Regional Disarmament Branch
  • Conference on Disarmament Secretariat and Conference Support Branch
Department of Peace Operations
Department of Operational Support
  • Department of Operational Support (DOS)
  • Office of the Under-Secretary-General (OUSG)
  • Office of Support Operations (OSO) 
  • Office of Supply Chain Management (OSCM) 
  • Division for Special Activities (DSA) 
  • Division of Administration, New York (DOA)
  • Office of Information and Communication Technology
Office for the Coordination of Humanitarian Affairs
Office of Counter-Terrorism (OCT)
Department of Economic and Social Affairs
Department for General Assembly and Conference Management
Department of Global Communications
Department of Safety and Security
  • Field Support Service
  • Division of Regional Operations
  • Division of Headquarters Security and Safety Services
Department of Management Strategy, Policy and Compliance
Internal Justice Bodies
Other Offices
Special Advisers, Representatives and Envoys

Offices Outside the Main Headquarters


UN Regional Commissions

Addis Ababa

See also UN System chart

Drupal template developed by DGC Web Services Section and Digital Soutions and Support Unit