Known family members
- Plunkett — presumed co-owner of Concordia and Plunkett Musical Instruments
- Josiah Plunkett — a Quidditch referee
- Mirabella Plunkett — a witch famous for falling in love with a merman
- Samuel Plunkett — a wizard infamous for shrunk a village
The surname Plunkett, though common in Ireland, is ultimately of French origin. It may be a habatational name derived from the name of the village of Plouquenet in Ille-et-Villaine, Brittany, itself meaning "parish of Guenec," from Breton plou, "parish," and Guenec, a personal name (derived from guen, "white") belonging to a saint. It may also derive from an occupational name for a person who made or sold blankets, from Middle English blaunket, from Anglo-Norman French blancquet, a diminutive form of blanc, "white."