Lucas More Plunket of Killeen, County Meath (born before 1602, died 29 March 1637), styled Lucas Môr, tenth lord Killeen, was created Earl of Fingall on 26 September 1628, was an Irish peer.
Plunket was the elder son of Christopher Plunket, 9th Baron Killeen, and Jenet, daughter of Sir Lucas Dillon. He succeeded to the barony in January 1613.
Plunket was conferred as Earl of Fingall by King's letter of 26 September 1628,"on account of the good testimony which the King had received as to his honour and virtue, and for the encouragement of his continuance in such courses". He was granted 2,400 acres in County Cavan; he was one of the founders of the town of Virginia, County Cavan. He sat on the Lords Committee for Privileges.
Plunket married first Elizabeth FitzGerald, daughter of Henry FitzGerald, 12th Earl of Kildare.
Plunket married secondly Susannah, daughter of Edward, lord Brabazon. They had two sons Christopher, who succeeded as 2nd Earl, and George, from whom later Earls of Fingall were descended; and a daughter, Eleanor, who married Andrew Nugent.
Plunket married thirdly Eleanor, daughter of Dudley Bagenal.
He married fourthly Margaret, daughter of Nicholas St Lawrence, 9th Baron Howth and his second wife Mary White.