German controversialist—a Christianized Jew—and opponent of Jewish literature, whose dispute with the Humanist and Hebraist Johannes Reuchlin (Reuchlin, Johannes) (q.v.) was a European cause célèbre in the early 16th century.

Pfefferkorn began a campaign to rid Germany of Jewish writings that were suspected of being subversive of Christianity. The Dominicans of Cologne supported him, and in 1509 he succeeded in persuading Emperor Maximilian I to issue a mandate permitting the confiscation and destruction of Hebrew books. Strong protests, however, forced the Emperor to seek the advice of theologians and scholars, including Reuchlin. Reuchlin's defense of many Jewish writings provoked fanatical recriminations from Pfefferkorn, resulting in a war of pamphlets and culminating in a widespread controversy between conservative scholars and the Humanists, who often caricatured Pfefferkorn in their popular writings.