Candide, ou l'Optimisme is a French satire written by Voltaire, a philosopher of the Age of Enlightenment, first published in 1759. The novella has been widely translated, with English versions titled Candide: or, All for the Best (1759); Candide: or, The Optimist (1762); and Candide: Optimism (1947). A young man, Candide, lives a sheltered life in an Edenic paradise, being indoctrinated with Leibnizian optimism by his mentor, Professor Pangloss. This lifestyle is abruptly ended, followed by Candide's slow and painful disillusionment as he witnesses and experiences great hardships in the world. Voltaire concludes Candide with, if not rejecting Leibnizian optimism outright, advocating a deeply practical precept, "we must cultivate our garden", in lieu of the Leibnizian mantra of Pangloss, "all is for the best" in the "best of all possible worlds".

Candide is characterized by its tone as well as its erratic, fantastical, and fast-moving plot. A picaresque novel with a story akin to a serious bildungsroman, it parodies many adventure and romance clichés, in a tone that is bitter and matter-of-fact.