Lettice Digby, 1st Baroness Offaly

Lettice FitzGerald, 1st Baroness Offaly (c.1580 – 1 December 1658) was an Irish noblewoman and a member of the FitzGerald dynasty. Although she became heiress-general to the Earls of Kildare on the death of her father, the title instead went to the next FitzGerald male heir when her grandfather, the 11th Earl of Kildare died in 1585. In 1620 she was created suo jure Baroness Offaly by King James I of England.

She was the wife of Sir Robert Digby, a landed English aristocrat by whom she had ten children. They were a notoriously litigious couple, who spent many years asserting their rights before numerous courts, and were quite prepared to sue even their closest relatives and accuse them of wrongdoing.

In early 1642, at the age of about sixty-two, her castle of Geashill was besieged by a force of insurgents from the O'Dempsey clan; she managed to hold out against them until October 1642. Her defence has been described as having been the "most spirited episode in the history of the Irish Rebellion of 1641".

Lettice was born in about 1580, the only child and heir of Gerald FitzGerald, Lord Offaly by Catherine Knollys, who was a younger daughter of Catherine Carey and Sir Francis Knollys. Lettice's maternal great-grandmother was Mary Boleyn, elder sister of Anne Boleyn, the second queen consort of King Henry VIII of England, who had been the lover of Mary prior to his courtship of Anne and possibly the biological father of her daughter Catherine. Her paternal grandparents were Gerald FitzGerald, 11th Earl of Kildare and Mabel Browne. One of her aunts, and after whom she was likely named, was Lettice Knollys, the celebrated rival of Queen Elizabeth I, who was also a distant cousin.