Emma Peel was a fictional television spy played by Diana Rigg on the 1960s British series The Avengers. Mrs. Peel was the partner of John Steed, and their pairing is considered by most viewers to showcase the definitive episodes of the series.

Mrs. Peel's character was notable for a number of characteristics. She is definitely a feminist heroine, eschewing traditional "damsel-in-distress" portrayals of women (she is rarely bested in any fight and rescues Steed as often as he rescues her). She's a master of martial arts and a formidable fencer. A certified genius, she specializes in chemistry and other sciences. In one episode, viewers even see her painting.

Her mod style of dress typified the period, and the character is still a paragon of style. Fashionwise, she's best-remembered for the leather catsuit she often wore in her first season. She drove a convertible Lotus Elan coupe at high speeds, and convincingly portrayed any series of undercover roles, from nurse to nanny. Her favorite guise was perhaps that of a women's magazine reporter, trying to interview big business tycoons and rich playboys.

Mrs. Peel's interactions with Steed range from the witty to the sexy. Both actors played the sexual tension aspect of their partnership so skillfully that it was perhaps not equalled until the pairing of Fox Mulder and Dana Scully. Unlike that later pairing, however, the tension was never broken except for a chaste peck on the cheek Emma gives Steed at the end of her final episode.

Mrs. Peel's husband, Peter Peel, was a test pilot and was lost on a mission. In Rigg's final episode on the show, "The Forget Me Knot", Mrs. Peel learns that her husband (who looks suspiciously like Steed from a distance) has returned, and she leaves Steed and her spy career behind.

The character appeared one last time in an episode of The New Avengers entitled "K is for Kill". Rigg had declined an offer to appear on the series, so stock footage of her from an Avengers episode was used instead.

The character was rehashed in a 1998 film version of the show, with Uma Thurman playing the role of Mrs. Peel and Ralph Fiennes playing Steed. Her portrayal received neither critical nor popular acclaim.