Marion St John Webb (1888-1930) was an English writer of novels and poetry for children. She was the daughter of the poet Arthur St. John Adcock. Many of her books remain in print. The latest edition of her 1917 novel Knock Three Times! was published in 1994 by Wordsworth Editions Ltd (reprinted 2007).A memorial notice was published in The Queenslander on 2 October 1930.