Sir William Norreys (c.1441 – before 10 January 1507) was a famous Lancastrian soldier, and later an Esquire of the Body to King Edward IV.
Probably born at Yattendon Castle, William was the eldest son of Sir John Norreys of Ockwells and Yattendon and Lady Alice Merbrook, Lady of the Garter. Upon the death of his father, he inherited all of the family's properties, including Yattendon Castle, but excluding Ockwells, which he inherited in 1494 upon the death of his stepmother.
William was a Lancastrian soldier in the Royal Army during the Wars of the Roses. He was knighted by King Henry VI at the Battle of Northampton, on 10 July 1460, when he was 20 years old. He was present at the Battle of Towton, on 29 March 1461, the largest and bloodiest battle of the wars. Though he survived the battle, when so few Lancastrians did, he was forced to make peace with the recently proclaimed King Edward IV.
Like his father, William adjusted to the new monarchy. By August 1461, he was appointed Steward of both the Royal manors of Cookham and Bray, adjoining his family estate of Ockwells. He was later appointed steward of nearby Foliejon Manor in Winkfield, in 1474.