Welles, William (c.1410–1463), chancellor of Ireland, was the younger son of Eon (John) de Welles, Lord Welles, and his wife Maud, daughter of Ralph, Lord Greystoke. He had a long career in the service of Richard (qv), duke of York, in Ireland. He was appointed to the office of seneschal of the liberty of Meath by York in 1432 and reappointed in 1436, 1442, and 1446; York also made a life grant of his lands in Kilkenny and Tipperary to Welles in 1435. Welles also held posts within the administration of the lordship, the first being the position of deputy lieutenant to his brother Lionel, Lord Welles, which he held from mid-February 1439 to late May or early June 1440, while the lieutenant was in Ireland. Welles's period as deputy was interrupted when he was kidnapped by two brothers of Thomas fitz Gerald, prior of Kilmainham, probably because he was seen to be a supporter of his cousin, James Butler (qv), 4th earl of Ormond.
Welles also served as the escheator of Ireland from the early 1440s till deprived of his office by the Talbot faction in 1445. Nevertheless, his activities in Meath made him willing to work with the lieutenant, John Talbot (qv), 1st earl of Shrewsbury, against the O'Farrells in 1446, and he received a parliamentary subsidy to recover his expenses in the defence of Meath. He was replaced as seneschal of the liberty of Meath in August 1449 when York came to Ireland, but was retained as escheator of the liberty (a position he held till at earliest 1455) and was knighted by the lieutenant. Welles accompanied York to Ulster and acted as one of his commissioners to treat with Eóghan Ó Neill (qv), was reappointed seneschal of the liberty of Meath on 26 August 1450, and appears to have held the office till his death. In September 1450 he was granted the temporalities of the diocese of Dublin to hold during the vacancy. He served as deputy chancellor to the absentee John Talbot, 2nd earl of Shrewsbury, from August 1454 till sometime before April 1458.
Welles actively supported York when he returned to Ireland in 1459, and was exempted from the act of resumption passed in the Irish parliament in 1460. He was further rewarded by York's son in 1461, when Edward IV granted him the offices of chancellor and chief butler of Ireland in July, offices that Welles retained till his death in 1463.