Peter Pan in Scarlet is a 2006 novel by British author Geraldine McCaughrean. It is the official sequel to J. M. Barrie's Peter and Wendy (1911), as it was authorised by Great Ormond Street Hospital, which was granted all rights to the characters and original writings by Barrie in 1929. McCaughrean was selected in 2004 following a competition in which novelists were invited to submit a sample chapter and plot outline for a sequel. Set in 1926, the book continues the story of the Lost Boys, the Darling family, and Peter Pan, during the reign of George V and following World War I.

Geraldine McCaughrean is a British children's novelist. She has written more than 170 books, including Peter Pan in Scarlet (2004), the official sequel to Peter Pan commissioned by Great Ormond Street Hospital, the holder of Peter Pan's copyright. Her work has been translated into 44 languages worldwide. She has received the Carnegie Medal twice and the Michael L. Printz Award among others.