Macnee began his career on stage in the early days of World War II, appearing in a production of "When We Are Married" in the provinces of his native England in 1940. A year later, he made his London debut as Laurie, the stalwart young male lead, in "Little Women". He toured with "Little Women" until called to military service in the navy from 1942-44. After the war, he broke into features with a small part in "The Life and Death of Colonel Blimp" (1945). Macnee joined David Niven in "The Elusive Pimpernel" (1950) and continued with decidedly supporting roles in films. He was Young Marley in the 1951 version of "A Christmas Carol", starring Alastair Sim, and was on board with Anthony Quayle chasing the German Navy during WWII in "Pursuit of the Graf Spee" (1957). By the 60s, Macnee's film career, which never reached the star grade, had petered out, although he would return to the big screen in character roles later on, notably as a teaching physician in "Young Doctors in Love" (1982) and as the record company owner in "This Is Spinal Tap" (1984).
Macnee found real success on the small screen, After debuting as Laertes in a 1947 BBC production of "Hamlet", he went on to frequent appearances on American TV in the anthology series so prevalent during that era. Mcnee was a particular favorite of Alfred Hitchcock, who employed the actor in several episodes of CBS' "Alfred Hitchcock Presents". But it was back in Britain that the actor found his signature role, John Steed. Macnee was first teamed with a male partner (played by Ian Hendrey) before being joined by a string of females: Catherine Gale (Honor Blackman), Mrs. Emma Peel (Diana Rigg) and Tara King (Linda Thorson). The show proved to be an international success with a cult following that continues to today.
Mcnee made his Broadway debut as the star of Anthony Shaffer's mystery "Sleuth" (1972) and subsequently headlined the national tour. He continued to appear in TV-movies and miniseries, including as a charming con man in "Mr. Jericho" (ABC, 1970) and as Dr. Watson in NBC's "Sherlock Holmes in New York" (1976), a role he later reprised in two syndicated TV-movies in 1992. He briefly reprised his most famous role, now teamed with Joanna Lumley in "The New Avengers" (1976 in the UK, CBS, 1978-79 in the USA). From 1981-82, he starred in the Australian series "For the Term of His Natural Life", then returned to the USA for several failed attempts: "Gavilan" (NBC, 1982), "Empire" (CBS, 1984) and "Lime Street" (ABC, 1985). Mcnee also found work in several low-budget horror films, including "Waxwork" (1988), as the wheelchair-bound Sir Wilfred out to save the world, and its sequel, "Waxwork II: Lost in Time", released direct-to-video in 1992. More recently, he had made a cameo appearance in the feature version of "The Avengers" (1998) with Ralph Fiennes and Uma Thurman.