Her Majesty's Civil Service

Her Majesty's Home Civil Service, also known as Her Majesty's Civil Service or the Home Civil Service, is the permanent bureaucracy or secretariat of Crown employees that supports Her Majesty's Government of the United Kingdom, which is composed of a cabinet of ministers chosen by the Prime Minister of the United Kingdom, as well as three devolved administrations: the Welsh Assembly Government, the Scottish Government and the Northern Ireland Executive.

The executive decisions of government ministers are implemented by HM Civil Service. Civil servants are employees of the Crown and not the British Parliament. Civil servants also have some traditional and statutory responsibilities which to some extent protect them from being used for the political advantage of the party in power. Senior civil servants may be called to account to Parliament.

In general use, the term civil servant in the United Kingdom does not include all public sector employees; although there is no fixed legal definition, the term is usually defined as "a servant of the Crown working in a civil capacity who is not the holder of a political (or judicial) office; the holder of certain other offices in respect of whose tenure of office special provision has been made; a servant of the Crown in a personal capacity paid from the Civil List". As such, the civil service does not include government ministers (who are politically appointed), members of the British Armed Forces, police officers, local government officials, members of the National Health Service (NHS), or staff of the Royal Household. As of 2007, there are approximately 532,000 (499,000 full-time equivalent) civil servants in the Home Civil Service.

There are two other administratively separate civil services in the United Kingdom. One is for Northern Ireland (the Northern Ireland Civil Service); the other is the foreign service (Her Majesty's Diplomatic Service). The heads of these services are members of the Permanent Secretaries Management Group.