The Philosophical Dictionary is an encyclopedic dictionary published by the Enlightenment thinker Voltaire in 1764. The alphabetically arranged articles often criticize the Roman Catholic Church, Judaism, Islam, and other institutions.

François-Marie Arouet (21 November 1694 – 30 May 1778) was a French Enlightenment writer, philosopher (philosophe) and historian. Known by his nom de plume M. de Voltaire he was famous for his wit, in addition to his criticism of Christianity—especially of the Roman Catholic Church—and of slavery. Voltaire was an advocate of freedom of speech, freedom of religion and separation of church and state.