William Parr, 1st Baron Parr of Horton

William Parr, 1st Baron Parr of Horton (c. 1483 – 10 September 1547 ) was the son of Sir William Parr and his second wife, the Hon. Elizabeth Fitzhugh, later Lady Vaux of Harrowden.

Life William Parr was a military man who fought in France, where he was knighted by King Henry VIII at Tournai Cathedral, and Scotland. Parr seemed to be uncomfortable in court circles and insecure in securing relationships. Nonetheless, he accompanied the King at the 'Field of the Cloth of Gold' in France. Like his brother, Sir Thomas Parr, William flourished under Sir Nicholas Vaux.

William was also a family man. After the death of his brother, Sir Thomas, William's sister-in-law Maud, widowed at age 25, called upon him to help in financial matters and to manage her estates in North England while she was busy in the south securing a future for her three children. William had been named one of the executors of his brother's will. Along with Cuthbert Tunstall, a distant kinsman of the Parr's, they provided the kind of protection and father figure which was missing in the lives of Maud's children. William's children were educated alongside Maud's children. He was elected to parliament as knight of the shire for Northamptonshire in 1529 and 1539.

He was made a peer of the realm as 1st Baron Parr of Horton, Northamptonshire on 23 December 1543. Upon his death in 1547 he was buried at Horton, where the inscription on his monument wrongly gives his year of death as 1546. With no male heirs, the barony became extinct. Maud (Magdalen) Parr, who married Sir Ralph Lane of Orlingbury. She was with her cousin as Dowager queen and was one of her ladies at Sudeley Castle. Elizabeth Parr, who married Sir Nicholas Wodhull (modern spelling: Woodhull).

Lord Parr and his wife are ancestors of William, Prince of Wales through his late mother, Diana, Princess of Wales. They descend from both Maud, Lady Lane and Mary, Lady Tresham.

He is buried at Horton where the family estate was.