Chief Constable is the title given to the commanding officer of every territorial police force in the United Kingdom except the two responsible for Greater London. As there are fifty six police forces in the United Kingdom, a chief constable is typically responsible for the policing of an area with a population of around a million people, and the actual number varies from a few hundred thousand to two or three million. A chief constable has no superior officer, but is responsible to the local police authority.

The title is a derived from the original local parish constables of the eighteenth century and earlier. Constable and Constabulary were terms adopted in an attempt to provide a historical link with the older forces and to emphasise local control. Much of the debate about policing in the early nineteenth century when modern police forces were introduced in Great Britain concerned fears that the new forces might become paramilitary agents of central government control. To this day other British police ranks, such as Inspector and Superintendent, are determinedly non-paramilitary--only Police Sergeants hold a quasi-military rank.

The Chief Constable's badge of rank, worn on the epaulettes, consists of crossed tipstaves in a wreath, surmounted by a crown.

Each Chief Constable is assisted by a Deputy Chief Constable (DCC), who wears crossed tipstaves in a wreath surmounted by a star ("pip"), and one or more Assistant Chief Constables (ACC), who wear the crossed tipstaves in a wreath alone. The Chief Constable, DCC and ACCs are collectively known as the "Chief Officers" of a force and belong to the Association of Chief Police Officers (ACPO).

The rank of Deputy Chief Constable was abolished on 1 April 1995 following recommendations made in the Sheehy Report . The Home Office officially reintroduced the rank on 1 January 2002.

In London the Metropolitan Police (formed in 1829) and the City of London Police (formed in 1839) are led by a Commissioner rather than a Chief Constable. This resulted from a fear of politicians gaining control of the police – in 1829 two justices of the peace were appointed to head the new Metropolitan Police. Even into the twentieth century the Commissioner of Police of the Metropolis was technically not a police officer at all, but a Magistrate, who thus held a Commission of the Peace .