The Avengers is a British television adventure series about secret agents in 1960s Britain. The programmes were made by TV company ABC Weekend Television (from July 1968 they were produced by Thames Television), and created by its Head of Drama Sydney Newman. It was an early example of the spy-fi genre, often combining secret agent storylines with science fiction and fantasy elements, preceding the James Bond film series. Running from 1961 to 1969, it is the longest running espionage series produced for English-language television, though the American series Mission: Impossible had more episodes (171).

By 1969, The Avengers was syndicated in over 90 countries. As a filmed series, music was specially composed for each episode by Laurie Johnson, assisted in the last season by Howard Blake (owing to Johnson's busy schedule writing for the film Hot Millions). The original 1961 series was sparsely dubbed with library music, but opened with a jazz-influenced theme by John Dankworth.