Major The Hon. John Wickham Gascoyne Beresford Steed usually known as John Steed, is a fictional character and the central protagonist on the 1960s British spy series The Avengers and its 1970s sequel The New Avengers, played by Patrick Macnee in both; by Donald Monat in the South-African radio series adaptation of The Avengers; by Ralph Fiennes in the 1998 film of the same name and by Julian Wadham in various audio adventures from Big Finish Productions.

The Avengers is a British espionage television series, created in 1961, that ran for 161 episodes until 1969. It initially focused on David Keel, aided by John Steed. Hendry left after the first series; Steed then became the main character, partnered with a succession of assistants. His most famous assistants were intelligent, stylish, and assertive women: Cathy Gale, Emma Peel, and Tara King. Dresses and suits for the series were made by Pierre Cardin.