The Baron of Westphalia's children, Cunegonde and Maximillian, together with Candide, his illegitimate nephew, and a servant girl, Paquette, are instructed in the Philosophy of Optimism by Dr. Pangloss, who tells them that "all is for the best in this best of all possible worlds." When Candide and Cunegonde have the temerity to fall in love, Candide is banished. Westphalia is subsequently invaded by the Bulgarians and Candide is told that Cunegonde and her family have been killed.

After a number of misadventures, Candide meets up with Pangloss in Portugal where they are arrested by the Spanish Inquisition for their liberal proclamations. Pangloss is to be hanged, but Candide evades punishment and, with the help of an Old Lady, is reunited with Cunegonde. She had not been killed but abducted, and is now the mistress of two wealthy men. Candide inadvertently kills the two men and the three escape.

On their way to the New World, Candide is again separated from Cunegonde, but meets up with Paquette and Maximillian, who survived the Bulgarian invasion. After accidentally stabbing Maximillian in an argument, Paquette and Candide set off for the fabled Eldorado. Despite the perfection of their surroundings, however, Candide is determined to find his true love. Once reunited, the group, including Maximillian and the Old Lady, decides to seek out "the wisest man in the world." Arriving at the wise man's cave, they are surprised to find that he is the venerable Dr. Pangloss. Having survived the hanging, Pangloss now proclaims a new philosophy that the group readily adopts: settle for the life one is given and "make [your] garden grow."