Joan Willoughby, born circa 1425, was the daughter of Robert Willoughby, 6th Baron Willoughby de Eresby, and his first wife, Elizabeth Montagu, daughter of John Montagu, 3rd Earl of Salisbury, by his first wife, Maud Francis, daughter of Adam Francis, Lord Mayor of London.
Her husband, Richard Welles, 7th Baron Welles, in consequence of their marriage, was summoned to Parliament from 26 May 1455 to 10 August 1469 as Ricardo Welles de Willughby, thus becoming Lord Willoughby.