The Indian Civil Service (ICS), which after 1886 was officially called the Imperial Civil Service and was also known as the British India Civil Service, was the élite higher civil service of the Government of India in the period of the British Raj. Its members were appointed under Section XXXII of the Government of India Act, 1858 of the Parliament of the United Kingdom.

At first almost all the top 1000 officials were British, and were educated in the best British schools. By 1914 5% were Indian. In 1942 there were 597 Indians and 588 British; most of the latter left at the time of independence.

At the time of the Partition of India in 1947, the ICS was divided between India and Pakistan. Although these are now organised differently, the contemporary Civil Services of India and the Pakistan Civil Service are both descended from the old ICS.

Historians often rate the ICS, together with the railway system, the legal system and the army, as among the most important legacies of the British rule in India.

The term civil service has two different meanings:

A civil servant or public servant is a person in the public sector employed for a government department or agency. The term explicitly excludes the armed services, although civilian officials can work at "Defence Ministry" headquarters. The extent of civil servants of a state as part of the "Civil Service" varies from country to country. In the United Kingdom, for instance, only Crown employees are referred to as civil servants, county or city employees are not.

Many consider the study of civil service to be a part of the field of public administration. Workers in "non-departmental public bodies" (sometimes called "QUANGOs") may also be classed as civil servants for the purpose of statistics and possibly for their terms and conditions. Collectively a state's civil servants form its Civil Service or Public Service.

An international civil servant or international staff member is a civilian employee that is employed by an international organisation. These international civil servants do not resort under any national legislation (from which they have immunity of jurisdiction) but are governed by an internal staff regulation. All disputes related to international civil service are brought before special tribunals created by these international organisations such as, for instance, the Administrative Tribunal of the ILO.