Sir William Courtenay (c. 1529 – 29 September 1557) was a landowner in Devon and de jure 2nd Earl of Devon.

He succeeded his grandfather Sir William Courtenay, of Powderham in 1535.

[1] Around 28 November 1545, he married Lady Elizabeth (c. 1533 – 4 Nov. 1576), daughter to John Paulet, 2nd Marquess of Winchester and his first wife, Elizabeth Willoughby, by whom he had a son and a daughter:[1][2][3] He took part in the battle of St. Quentin in August 1557 in Picardy, France, and died on 29 September 1557.

[7] His widow later married Sir Henry Ughtred, son of Sir Anthony Ughtred and his second wife, Elizabeth Seymour, sister of Jane, third consort of Henry VIII.

[8][9] In 1831, a decision of the House of Lords determined that he had succeeded his sixth cousin once removed (Edward Courtenay, 1st Earl of Devon) as de jure 2nd Earl of Devon in 1556.