Randal Hume Keynes, OBE, FLS (born July 29, 1948)[1] is a British conservationist, author and great-great-grandson of Charles Darwin. He is the author of the intimate exploration of his famous ancestry, Annie's Box, subtitled Darwin, His Daughter, and Human Evolution (2001), a book about the relationship between Darwin and his daughter Annie, whose early death deeply affected him and his views on religion.[2]

He has taken a leading role in the campaign to have Down House, Darwin's former home, designated a World Heritage Site.[3]

Keynes is the son of the Hon. Anne Pinsent (née Adrian) and physiologist Richard Keynes.[1] He is the great-nephew of the economist John Maynard Keynes and the brother of the historian and Cambridge professor Simon Keynes. He is the grandson of the surgeon Geoffrey Keynes, Nobel Prize-winning physiologist Edgar Douglas Adrian, 1st Baron Adrian, and Hester Adrian, Baroness Adrian.

Keynes' son, Skandar (born 1991), is an actor best known for his role as Edmund Pevensie in the Narnia films. He also has a daughter, Soumaya Keynes (born 1989), who has appeared in various productions for BBC Radio 4.

He is a distinguished supporter of the British Humanist Association.[4