Sir Nicholas Plunkett (1602–1680) was an Anglo-Irish lawyer and politician. The son of Christopher Plunkett, 9th Baron Killeen and Jane (or Genet) Dillon, daughter of Sir Lucas Dillon, his brother Luke was created Earl of Fingall in 1628. At the age of twenty Plunkett traveled to London to receive training as a lawyer at Gray's Inn in London, and later trained at King's Inn in Dublin. By the 1630s he had established a thriving legal practice: the attempts by Thomas Wentworth, the Lord Lieutenant of Ireland, to confiscate as much Irish land as possible to the Crown, ensured that his services were in high demand. At this time he also became an MP in the Irish House of Commons, sitting for Meath.