The French Dominican William Peraldus or Guillaume Peyraut (died c. 1275), well known for his long summae on the vices and virtues, also produced several cycles of sermons, of which two deal with the Epistle and the Gospel readings for the Sundays of the Church year. This study analyzes the latter in some detail and argues that, rather than collecting sermons he had preached earlier, Peraldus wrote these sermons systematically for the use of other preachers. The Epistle sermons for the first Sunday in Advent and the Gospel sermons for the third Sunday in Advent are presented in their original Latin text together with an English translation in order to demonstrate how Peraldus dealt with the biblical text as well as his moral concerns and his literary style. The selected texts are then compared with several other major cycles produced in France in Peraldus's time. Like his summae on the vices and the virtues, Peraldus's sermons became very popular in medieval Europe, as is witnessed by selective copying and citations that can be seen in a number of instances primarily from the sermon literature of later medieval England. One aspect of this popularity is the adaptation of his material into a genuine sermon, as it can be found in the sermons attributed to Repingdon, of which one is here examined in detail.