Callan is a British action-drama spy television series created by James Mitchell, first airing between 1967 and 1972.

It starred Edward Woodward as David Callan, an agent of a state secret service dealing with internal security threats to the United Kingdom. Though portrayed as having responsibilities similar to those of the real-life MI5, Callan's fictional "Section" has carte blanche to use the most ruthless of methods. In the storylines, interrogation is by means of torture, while extrajudicial killings are so routine, they have a colour-coded filing system.

Despite being an assassin who stays in the socially isolating job because it is the only thing at which he is good, Callan is a sympathetic character by comparison to his often-sadistic upper-class colleagues and implacable superiors. The downbeat cover for the Section's headquarters was a scrap-metal business in a former school, belonging to "Charlie Hunter"—an alias inherited by each of Callan’s superiors.

Produced by ABC Weekend TV and Thames Television, the programme proved extremely popular; in addition to four series between 1967 and 1972, a feature-length film was released in 1974, and a TV film produced by Associated Television in 1981 was aired.