William of Sherwood, or Shyreswood, was an English logician. All that is known for certain of William of Sherwood's life is that in 1252 he was a master at Oxford, that he became treasurer of the cathedral church of Lincoln soon after 1254, that he was rector of Aylesbury and of Attleborough, that he was still living in 1266, and that he was dead in 1271. From references in his works, however, and from the fact that his logic almost certainly had a direct influence on the logical writings of Peter of Spain, Lambert of Auxerre, Albert the Great, and Thomas Aquinas, all of whom were at Paris around the same time, it seems undeniable that he taught logic there from about 1235 to about 1250.

William's impact on his contemporaries went unacknowledged except by Roger Bacon, who, in his Opus Tertium (1267), described him as "much wiser than...