Daughter of the second Baron Glenconner and Elizabeth Lady Glenconner, Emma Tennant was born in London in 1937. Educated at St Paul's Girls School, she spent the war years and her childhood summers at Glen, the family castle in the Borders, and was one of the last debutantes to be presented at court. Growing up in swinging London in the '50s and '60s, she took an active part in the social and creative life of the city working as a travel writer for Queen magazine and then as features editor for Vogue. Her first novel, The Colour of Rain, was published in 1963 under the name Catherine Aydy. Married three times, with a son and two daughters, she became a full-time novelist in 1973 with the apocalyptic The Time of the Crack, later reprinted as The Crack. More than twenty books were to follow, including thrillers, comic fantasies, books for children and a series of unconventional and revisionary 'sequels' to classic texts such as Tess (1993) or Emma in Love (1996).
Tennant's interest in archetypal; narratives and especially in how women are placed in them has led her to reinterpret other canonical texts in a characteristic voice which blends witty fable, social satire, a feminist analysis of patriarchal power, and an engagement with divided identify, which she sees as a theme particularly close to Scottish experience.
More recent work has seen Tennant turn a reflective eye on her own life. She was the founding editor of the innovative periodical Bananas (1975); she has worked as general editor of In Verse (1982) and as general editor of the Viking series Lives of Modern Women (1985). She was awarded an honorary D.Lit. from the University of Aberdeen in 1996.