Headquarters (often referred to as HQ) notes the location where most or all of the important functions of an organization are coordinated. The term is used in a wide variety of situations, including private sector corporations, non-profits, military organizations, religious groups, sports leagues and so on. It usually implies a geographically dispersed organization with a clear hierarchical structure.

In the private sector, the corporate headquarters is the entity at the top of a corporation that takes responsibility for managing all business activities. The intended benefit of headquarters is to carry out purposeful regulatory capacity and ensure corporate governance. The corporate headquarters is a key element of a corporate structure and covers different corporate functions including strategic planning, corporate communications, tax payments, legal operations, marketing, finance, human resources, information technology, and procurement. This entity includes the chief executive officer (CEO) as a key person and their support staff such as the CEO office and other CEO-related functions; the "corporate policy making" functions, including all corporate functions necessary to steer the firm by defining and establishing corporate policies; the corporate services encompassing activities that combine or consolidate certain enterprise-wide needed support services, provided based upon specialized knowledge, best practices, and technology to serve internal (and sometimes external) customers and business partners; and the bidirectional interface between corporate headquarters and business units.

A headquarters normally includes the leader of a business unit and their staff, as well as all functions to manage the business unit and operational activities. The head of the business unit is responsible for overall result of the business unit.

A headquarters sometimes functions at the top of a regional unit, including all activities of the various business units, taking full responsibility for overall profitability and success of this regional unit.

Military headquarters take many forms, depending on the size and nature of the unit or formation they command. Typically, they are split into the forward, main and rear components, both within NATO nations, and those following the organization and doctrine of the former Soviet Union (see Isby, 1988).

The forward or tactical headquarters, known as "tac" for short, is a small group of staff and communicators. Usually very mobile, they exist to allow the commander to go forward in an operation, and command the key parts of it from a position where they can see the ground and influence their immediate subordinates.

The main HQs (known as 'main') is less mobile and is involved in both the planning and execution of operations. There are a number of staff assembled here from various staff branches to advise the commander, and to control the various aspects of planning and the conduct of discrete operations. A main HQ for a large formation will have a chief of staff (CoS) who coordinates the staff effort; in a smaller HQ this may be done by the second-in-command.

The rear or logistic headquarters is some distance from the battle or front line in conventional operations. Its function is to ensure the logistical support to front line troops, which it does by organizing the delivery of combat supplies, materiel and equipment to where they are needed, and by organizing services such as combat medicine, equipment recovery, and repair.