William Willoughby

William Willoughby may refer to:

• William Willoughby, 11th Baron Willoughby de Eresby (1482-1526), father of Katherine Willoughby and the largest landowner in Lincolnshire, England
• William Willoughby, 1st Baron Willoughby of Parham (c.1515 – 1570), English baron and nephew of the above
• William Willoughby (c.1566-1615), MP for Nottingham (UK Parliament constituency)
• William Willoughby, 3rd Baron Willoughby of Parham (1584 – 1617)
• Bill Willoughby (born 1957), American former basketball player