Sir William Welles ( 1409/10-1463 ) was an English-born statesman and judge in fifteenth-century Ireland, who held the office of Lord Chancellor of Ireland: he was the brother of Lionel de Welles, 6th Baron Welles, a prominent supporter of the House of Lancaster, who was killed at the Battle of Towton.
William was probably born in 1409 or 1410, second son of Eudo de Welles and Maud de Greystoke; his paternal grandfather was John de Welles, 5th Baron Welles. Eudo died before his father and William's brother Lionel succeeded his grandfather in 1421.
Lionel was appointed Lord Lieutenant of Ireland about 1438, and William acted as his brother's deputy; he was appointed deputy Chancellor in 1454 and Lord Chancellor of Ireland in 1461. Unlike his brother he does not seem to have been particularly active on behalf of Henry VI, and despite his brother's death at Towton and the family's strong links to the House of Lancaster was still in office a year after Towton. He died in 1463. His main residence was at Posseckstown, near Enfield, County Meath.
William married Anne Barnewall of Crickstown, County Meath. There are references in different sources to a son and at least two daughters. Little is known of his son: the daughters were-
- Elizabeth (died 1506): she married fiirstly Christopher Plunket, second Baron Killeen, and secondly James Fleming, 7th Baron Slane, and had children by both marriages including
- Ismay, who married Thomas Nangle, titular Baron Navan and had issue.
- Ross, Charles Edward IV Eyre Methuen London 1974
- Ball F. Elrington The Judges in Ireland 1221-1921 John Murray London 1926
- Cokayne The Complete Peerage