William Grimsby or Grymesby (1420–1482) was an English courtier and parliamentarian, a member of the Lancastrian faction in the Wars of the Roses. Grimsby was returned as Member of the Parliament of England for Great Grimsby in the Parliament of February 1449, and later was appointed to a series of court offices under Henry VI - Yeoman of the Crown (1454-57), Treasurer of the Chamber (1456-60), and Squire of the Body (1457-61). He was returned to Parliament for Lincolnshire in 1459 (the Parliament of Devils), and was awarded some of the lands it confiscated from Yorkist nobles.