Mary Elizabeth Braddon (4 October 1835 - 4 February 1915) was an English popular novelist of the Victorian era. She is best known for her 1862 sensation novel Lady Audley's Secret, which has also been dramatised and filmed several times.
Born in London, Mary Elizabeth Braddon was privately educated. Her mother Fanny separated from her father Henry in 1840, when Mary was five. When Mary was ten years old, her brother Edward Braddon left for India and later Australia, where he became Premier of Tasmania. Mary worked as an actress for three years, when she was befriended by Clara and Adelaide Biddle. They were only playing minor roles, but Braddon was able to support herself and her mother. Adelaide noted that Braddon's interest in acting waned as she took up writing novels.

In 1860, Mary met John Maxwell (1824-1895), a publisher of periodicals, and moved in with him in 1861. However, Maxwell was already married with five children, and a wife living in an mental asylum in Ireland. Mary acted as stepmother to his children until 1874, when Maxwell's wife died and they were able to get married. She had six children by him.

Her eldest daughter, Fanny Margaret Maxwell (1863-1955), married the naturalist Edmund Selous on 13 January 1886. In the 1920s they lived in Wyke Castle, where Fanny founded a local branch of the Woman's Institute in 1923, of which she became the first president.

The second eldest son was the novelist William Babington Maxwell (1866-1939).

Mary Elizabeth Braddon died on 4 February 1915 in Richmond (then in Surrey) and is interred in Richmond Cemetery. Her home had been Lichfield House in the centre of the town, which was replaced by a block of flats in 1936, Lichfield Court, now listed. She has a plaque in Richmond parish church, which calls her simply "Miss Braddon". A number of nearby streets are named after characters in her novels - her husband was a property developer in the area.