Zadig, ou La Destinée, ("Zadig, or The Book of Fate") (1747) is a famous novel written by the French Enlightenment philosopher Voltaire. It tells the story of Zadig, a philosopher in ancient Babylonia. The author does not attempt any historical accuracy, and some of the problems Zadig faces are thinly disguised references to social and political problems of Voltaire's own day.

The book is philosophical in nature, and presents human life as in the hands of a destiny beyond human control. It is a story of religious and metaphysical orthodoxy, both of which Voltaire challenges with his presentation of the moral revolution taking place in Zadig himself. Voltaire's skillful use of the literary devices of contradiction and juxtaposition are shown in beautiful form in this prose. Behind Candide, it is considered one of his most celebrated works.