Baron Plunket, of Newtown in the County of Cork, is a title in the Peerage of the United Kingdom. It was created in 1827 for the prominent Irish lawyer and Whig politician William Plunket. He served as Lord Chancellor of Ireland from 1830 and 1834 and again from 1835 to 1841. His eldest son, the second Baron, was Bishop of Tuam, Killala and Achonry between 1839 and 1866. He was succeeded by his younger brother, the third Baron. He was a barrister. His eldest son, the fourth Baron, served as Archbishop of Dublin between 1884 and 1897. He was succeeded by his eldest son, the fifth Baron. He was a diplomat and held office as Governor of New Zealand between 1904 and 1910. His grandson, the seventh Baron, was Equerry to both King George VI and Queen Elizabeth II. He was succeeded by his younger brother, the eighth and (As of 2010[update]) present holder of the title.
Two other members of the family have also gained distinction. The Hon. David Plunket, second son of the third Baron, was a Conservative politician and was created Baron Rathmore in 1895. The Most Reverend the Hon. Benjamin Plunket, second son of the fourth Baron, was Bishop of Meath from 1919 to 1925.
The seventh and eighth Barons were related to the Marquess of Londonderry. Their mother and wife of the sixth Baron was the illegitimate daughter of the actress Fannie Ward and Charles Vane-Tempest-Stewart, 7th Marquess of Londonderry. After sixth Baron and his wife were killed in an air accident in 1938 the three Plunket brothers were raised by the Lord and Lady Londonderry.
The heir presumptive is the present holder's brother the Hon. Shaun Albert Frederick Sheridan Plunket (b. 1931)