Sophie's World (Norwegian: Sofies verden) is a 1991 novel by Norwegian writer Jostein Gaarder. It follows the events of Sophie Amundsen, a teenage girl living in Norway, and Alberto Knox, a middle-aged philosopher who introduces her to philosophical thinking and the history of philosophy.
Sophie's World was originally written in Norwegian and became a best seller in Norway. It won the Deutscher Jugendliteraturpreis in 1994. The English version of the novel was published in 1995, and the book was reported to be the best-selling book in the world in that year. By 2011 the novel had been translated into fifty-nine languages, with over forty million copies in print. It is one of the most commercially successful Norwegian novels outside of Norway, and has been adapted into a film and a PC game.