The Moonstone (1868) by Wilkie Collins is a 19th-century British epistolary novel. It is generally considered to be the first detective novel, and it established many of the ground rules of the modern detective novel. The story was originally serialised in Charles Dickens's magazine All the Year Round. The Moonstone and The Woman in White are widely considered to be Collins's best novels, and Collins adapted The Moonstone for the stage in 1877, although the play was performed for only two months.

William Wilkie Collins (8 January 1824 – 23 September 1889) was an English novelist, playwright and short story writer best known for The Woman in White (1859) and The Moonstone (1868).