 He had an elder brother, Thomas (d.1559) and a sister, Margaret, who married Sir Matthew Arundell ("c." 1533 – 24 December 1598) of Wardour Castle.Francis Willoughby's father, Sir Henry Willoughby, had inherited Wollaton and other properties including 'lucrative coal pits' at the death of his uncle, Sir John Willoughby, on 10 January 1549.However, only a few months later, on 27 August 1549, Sir Henry Willoughby was slain on Mousehold Heath in the suppression of Kett's rebellion.