Sir William Butts (c. 1486 – 22 November 1545) was a member of King Henry VIII of England's court and served as the King's physician.
He had his portrait painted by Hans Holbein the Younger in 1543, and was knighted the following year. His granddaughter Anne was married to the son of Sir Nicholas Bacon.
Butts was educated at Gonville Hall Cambridge. He took his M.A. in 1509 and his M.D. in 1518.
The details of Butts' early life are unclear; he may have been born in either the London borough of Fulham or in Norfolk.
He was made a Member of the College of Physicians in 1529 and was knighted about 1545.
Butts died in 1545, and is buried at All Saints Church, Fulham, London.
He worked with George Owen and Thomas Wendy.
Butts was a known Protestant and close associate of Thomas Cranmer, Archbishop of Canterbury and Catherine Parr, the sixth wife of Henry VIII. His family later became significant leaders of the Puritan faction in Norfolk.
Butts had three children,