William de Karlell was an English-born judge, administrator and cleric in fourteenth-century Ireland. He held numerous benefices including Archdeacon of Meath and Rector of Youghal, and sat in the Irish House of Commons. After sitting for some years as a Baron of the Court of Exchequer (Ireland) he was removed from office, following a flood of complaints about his acts of extortion and oppression committed by himself and Chief Baron Holywood, but he was later restored to favour, and served briefly as Chief Baron of the Irish Exchequer. He is buried in St Canice's Cathedral, Kilkenny.

St Canice's Cathedral, also known as Kilkenny Cathedral, is a cathedral of the Church of Ireland in Kilkenny city, Ireland. It is in the ecclesiastical province of Dublin. Previously the cathedral of the Diocese of Ossory, it is now one of six cathedrals in the United Dioceses of Cashel and Ossory.