Anna Sewell (30 March 1820 – 25 April 1878) was an English novelist, best known as the author of the classic novel Black Beauty.

Anna Mary Sewell was born in Great Yarmouth, Norfolk, England into a devoutly Quaker family. Her father was Isaac Phillip Sewell (1793–1879), and her mother, Mary Wright Sewell (1798–1884) was a successful author of children's books. She had one sibling, a younger brother named Philip and was largely educated at home.

At the age of twelve, the family moved to Stoke Newington, where Sewell attended school for the first time. Two years later, however, she slipped while walking home from school and severely injured both of her ankles. Her father took a job in Brighton in 1836, in the hope that the climate there would help to cure her. Despite this, and most likely because of mistreatment of her injury, for the rest of her life Anna was unable to stand without a crutch or to walk for any length of time. For greater mobility, she frequently used horse-drawn carriages, which contributed to her love of horses and concern for the humane treatment of animals.

At about this time, both Anna and her mother left the Society of Friends to join the Church of England, though both remained active in evangelical circles. Her mother expressed her religious faith most noticeably by authoring a series of evangelical children's books, which Anna helped to edit, though all the Sewells, and Mary Sewell's family, the Wrights, engaged in many other good works.

While seeking to improve her health in Europe, Sewell encountered various writers, artists, and philosophers, to which her previous background had not exposed her.

Sewell's only published work was Black Beauty, written during 1871 to 1877, after she had moved to Old Catton, a village outside the city of Norwich in Norfolk. During this time her health was declining. She was often so weak that she was confined to her bed and writing was a challenge. She dictated the text to her mother and from 1876 began to write on slips of paper which her mother then transcribed.

Sewell sold the novel to local publisher Jarrolds on 24 November 1877, when she was 57 years of age. Although it is now considered a children's classic, she originally wrote it for those who worked with horses. She said "a special aim [was] to induce kindness, sympathy, and an understanding treatment of horses".

Sewell died of hepatitis or phthisis on 25 April 1878, five months after her book was published, living long enough to see the book's initial success. She was buried on 30 April 1878 in the Quaker burial-ground at Lammas near Buxton, Norfolk, not far from Norwich, where a wall plaque now marks her resting place.