An official is someone who holds an office (function or mandate, regardless whether it carries an actual working space with it) in an organisation or government and participates in the exercise of authority (either his own or that of his superior and/or employer, public or legally private).

A government official or functionary is an official who is involved in public administration or government, through either election, appointment, or employment. A bureaucrat is a member of the bureaucracy. An elected official is a person who is an official by virtue of an election. Officials may also be appointed ex officio (by virtue of another office, often in a specified capacity, such as presiding, advisory, secretary). Some official positions may be inherited.

A person who currently holds an office is referred to as an incumbent.

The word official as a noun has been recorded since the Middle English period, first seen in 1314. It comes from the Old French official (12th century), from the Latin officialis ("attendant to a magistrate, public official"), the noun use of the original adjective officialis ("of or belonging to duty, service, or office") from officium ("office"). The meaning "person in charge of some public work or duty" was first recorded in 1555. The adjective is first attested in English in 1533, via the Old French lang: oficial.

The informal term officialese, the jargon of "officialdom," was first recorded in 1884.

In Roman Antiquity

An officialis (plural officiales) was the official term (somewhat comparable to a modern civil servant) for any member of the officium (staff) of a high dignitary such as a governor.

Ecclesiastical judiciary

In Canon law, the word or its Latin original officialis is used absolutely as the legal title of a diocesan bishop's judicial vicar who shares the bishop's ordinary judicial power over the diocese and presides over the diocesan ecclesiastical court.

The 1983 Code of Canon Law gives precedence to the title Judicial Vicar, rather than that of Officialis (canon 1420). The Code of Canons of the Eastern Churches uses only the title Judicial Vicar (canon 191).

In German, the related noun Offizialat was also used for an official bureau in a diocese that did much of its administration, comprising the vicariate-general, an adjoined secretariat, a registry office and a chancery.

The title of official principal, together with that of vicar-general, has in Anglicanism? England been merged in that of Diocesan chancellor of a diocese.

Other officials

In sports, the term official is used to describe a person enforcing playing rules in the capacity of a linesman, referee and umpire; also specified by the discipline, e.g. American football official, Ice hockey official.