There have been two baronetcies granted to the Willyses of Fen Ditton, both in the Baronetage of England. The Willys Baronetcy, of Fen Ditton in Cambridgeshire, was first created in the Baronetage of England on 15 December 1641 for Thomas Willys, (the surname also appears as Willis, Wills, and Wyllys) son and heir of Richard Willys, of Fen Ditton and Horningsey, Cambridgeshire, by Jane, daughter and heir of William Henmarsh, of Balls, in Ware, Hertfordshire. Richard's brother, Thomas was Clerk of the Crown in Chancery.
Sir Richard Willis (knighted in 1642), the younger brother of Thomas, with the same parentage, was also created Baronet of Fen Ditton (on 11 June 1646). Sir Richard who fought as an officer in the Royalist army during the English Civil War, also worked as a double-agent for Oliver Cromwell during the Interregnum and was banned from court following the Restoration. Sir Richard's son Sir Thomas Fox Willis died in 1701 without issue, having been born, according to the medical notes made by his grandfather, Thomas Foxe, 'bereft of his wits'; this baronetcy therefore became extinct.
The baronetcy granted to Thomas Willys passed to his son John Willys (2nd Baronet), then to his grandson Thomas Willys (3rd Baronet), but his great-grandson, also Thomas Willys (4th Baronet), died without issue in 1725; the baronetcy passed to another Thomas Willys, the 4th Baronet's first cousin once removed (the son of John Willys (2nd Baronet)'s younger brother William). On his death in 1726 his younger brother William inherited the title, but died childless in 1732, making the baronetcy extinct.
John Walpole Willis and his descendants (some of whom became Willis-Bund, e.g. John William Willis-Bund) descended from this family through his grandfather Joseph Willis of Wakefield, Yorkshire . The anatomist, neurologist and psychologist Thomas Willis was a kinsman of this line; his father, Thomas, the son of another Thomas Willis (of Kennington, Oxfordshire, Berkshire prior to the 1974 boundary changes) was the steward of Great Bedwyn, Wiltshire and owned a farm there (http://galileo.rice.edu/Catalog/NewFiles/willis.html ; http://www.dana.org/news/cerebrum/detail.aspx?id=1336). The 6th Baronet served as M.P. for Great Bedwyn from 1727–1732.
Burke's 'A Genealogical and Heraldic History of the Commoners of Great Britain and Ireland, 1834' details the relationship between the Willys baronets and the Willis Fleming family of North Stoneham Park that descended from Thomas Willis thus: 'The family of Willis claims descent from the eminent and ennobled family of Welles. Browne Willis, M.P., the celebrated antiquarian, was one of its members, and his descendants have assumed of late years the surname Fleming, for estates left to them in Hampshire, where they are now resident. In the reign of Charles II, Thomas Willis, of the Berkshire family of that name, and to which family a baronetcy was granted by King Charles I, settled in Lancashire and purchased estates in that county, which, together with others, are now in possession of Richard Willis, esq. of Halsnead Park.'. Browne Willis was the anatomist Thomas Willis's grandson. The Richard Willis in question was, like Thomas Willis, a descendant of John Willis of Harborough, Lancashire, and so came to inherit the estates there.
Willys baronets, of Fen Ditton (1641)
- Sir Thomas Willys, 1st Baronet (1612–1701)
- Sir John Willys, 2nd Baronet (1636–1704)
- Sir Thomas Willys, 3rd Baronet (1674–1705)
- Sir Thomas Willys, 4th Baronet (1704–1725)
- Sir Thomas Willys, 5th Baronet (1680–1726)
- Sir William Willys, 6th Baronet (1685–1732)
- Extinct on his death
Willys baronets, of Fen Ditton (1646)
- Sir Richard Willis, 1st Baronet (1614–1690)
- Sir Thomas Fox Willis, 2nd Baronet (1642–1701)
- Extinct on his death
- Cokayne, George Edward, ed. (1902), Complete Baronetage 1625–1649, pp. 148,234,235
- Burke, John, ed. (1863), Burke's Genealogical and Heraldic Dictionary of the Landed Gentry, pp. 1673
- Burke, John, ed. (1834), A Genealogical and Heraldic History of the Commoners of Great Britain and Ireland, pp. 46
- Burke, John, ed. (1835), A Genealogical and Heraldic History of the Commoners of Great Britain and Ireland vol. II, pp. 374
- Burke, Sir Bernard (ed.), Burke's Genealogical and Heraldic Dictionary of the Landed Gentry, 4th edition, (Burke's Peerage Ltd, 1863)
- Burke, John and Burke, John Bernard (eds.), Burke's Genealogical and Heraldic History of the Extinct and Dormant Baronetcies of England, (C. Whittingham, 1838)
- Fetherston, J. (ed.), The Warwickshire Antiquarian Magazine Part I, (Henry T. Cooke and Son, 1859)