Elizabeth de Burgh, Duchess of Clarence, suo jure Countess of Ulster, born 1332, died 1363.
Elizabeth was the only child of William Donn de Burgh, 3rd Earl of Ulster, and a daughter of Henry Plantagenet, 3rd Earl of Leicester. She was the last of the senior legitimate line of the descendants of William de Burgh.

Upon William's murder in June 1333 she became the sole legal heir to all the de Burgh lands in Ireland. In actual fact, her kinsmen Sir Edmond Burke of Clanwilliam, Sir Edmond Albanach Bourke of Mac William Iochtar and Sir Ulick Burke of Clanricarde became the de facto heads of the family and owners of de Burgh land during the Burke Civil War 1333-38.

As Duchess of Ulster she was raised in England and married her cousin Lionel of Antwerp, 1st Duke of Clarence in 1352. He was the second son of Edward III of England and his Queen consort Philippa of Hainault.

They had an only child, Philippa Plantagenet, born in 1355. Philippa married in 1368 Edmund Mortimer, 3rd Earl of March (1351-1381). They were parents to Anne de Mortimer, grandparents to Richard Plantagenet, 3rd Duke of York and great-grandparents to Edward IV and Richard III.

Elizabeth died in Dublin in 1363 during her husband's term as Governor of Ireland.