In his far-ranging study, Rabelais and His World, Mikhail Bakhtin describes Erasmus’ Praise of Folly as the most complete expression in the Renaissance of Medieval Latin humour and as ‘one of the greatest creations of carnival laughter in world literature.’ For all Erasmus's wit and comic irony, the Praise of Folly might seem an unlikely embodiment of the comic spirit central to Carnival and other popular festivals such as New Year's, May Day, Midsummer, and the Twelve Days of Christmas. In the light of Bakhtin's remarks, however, I will here explore the importance of popular traditions of Carnival and other holiday celebrations for understanding the spirit and structure of Erasmus’ work.