Essais de Théodicée sur la bonté de Dieu, la liberté de l'homme et l'origine du mal ("Essays of theodicy on the goodness of God, the freedom of man and the origin of evil"), more simply known as Théodicée, is a book of philosophy by the German polymath Gottfried Leibniz. The book, published in 1710, introduced the term theodicy, and its optimistic approach to the problem of evil is thought to have inspired Candide (albeit satirically). Much of the work consists of a response to the ideas of Pierre Bayle, with whom Leibniz carried on a debate for many years.

Theodicy , in its most common form, attempts to answer the question why a good God permits the manifestation of evil. Theodicy addresses the evidential problem of evil by attempting “to make the existence of an All-knowing, All-powerful and All-good or omnibenevolent God consistent with the existence of evil” or suffering in the world. Unlike a defence, which tries to demonstrate that God's existence is logically possible in the light of evil, a theodicy provides a framework which claims to make God's existence probable. The German mathematician and philosopher Gottfried Leibniz coined the term "theodicy" in 1710 in his work Théodicée, though various responses to the problem of evil had been previously proposed. The British philosopher John Hick traced the history of moral theodicy in his 1966 work, Evil and the God of Love, identifying three major traditions:

1. the Plotinian theodicy, named after Plotinus
2. the Augustinian theodicy, which Hick based on the writings of Augustine of Hippo
3. the Irenaean theodicy, which Hick developed, based on the thinking of St. Irenaeus