John Christopher, English author (d. 2012)
Sam Youd (16 April 1922 – 3 February 2012), was a British writer, best known for science fiction written under the name of John Christopher, including the novels The Death of Grass, The Possessors, and the young-adult novel series The Tripods. He won the Guardian Children's Fiction Prize in 1971 and the Deutscher Jugendliteraturpreis in 1976.

Youd also wrote under variations of his own name and under the pseudonyms Stanley Winchester, Hilary Ford, William Godfrey, William Vine, Peter Graaf, Peter Nichols, and Anthony Rye.