Dame Antonia Susan Duffy (née Drabble; 24 August 1936 – 16 November 2023), known professionally by her former married name, A. S. Byatt, was an English critic, novelist, poet, and short story writer. Her books have been translated into more than thirty languages, reflecting the wide-reaching impact of her literary contributions.

After attending the University of Cambridge, Byatt married in 1959 and moved to Durham. It was during her time at university that she began working on her first two novels, Shadow of a Sun (1964; reprinted in 1991 with its originally intended title, The Shadow of the Sun) and The Game (1967). Tragically, in the same week she accepted a teaching job in 1972 to help pay for the education of her son, a drunk driver killed her son as he walked home from school. He was 11 years of age. Byatt spent a symbolic 11 years teaching, then began full-time writing in 1983. The Virgin in the Garden (1978) was the first of The Quartet, a tetralogy of novels that continued with Still Life (1985), Babel Tower (1996) and A Whistling Woman (2002).

Byatt's novel Possession: A Romance received the 1990 Booker Prize, while her short story collection The Djinn in the Nightingale's Eye (1994) received the 1995 Aga Khan Prize for Fiction. Her novel The Children's Book was shortlisted for the 2009 Booker Prize and won the 2010 James Tait Black Memorial Prize. Her critical work includes two studies of Dame Iris Murdoch, as well as other literary critiques such as Wordsworth and Coleridge in Their Time (1970) and Portraits in Fiction (2001).

A distinguished critic as well as a writer of fiction, Byatt was appointed CBE in 1990 and DBE in 1999. She was awarded the Shakespeare Prize in 2002, the Erasmus Prize in 2016, the Park Kyong-ni Prize in 2017, and the Hans Christian Andersen Literature Award in 2018. She was mentioned as a candidate for the Nobel Prize in Literature, underscoring her significant contributions to the field of literature.