Born: August 26, 1828, Dublin, Ireland.
Died: April 1, 1897, Dublin, Ireland.
Buried: Mount Jerome Cemetery, Dublin, Ireland.
Son of John Plunket, William was the 4th Baron Plunket.
He graduated from Cheltenham College and Trinity College, Dublin (1853).
He took Holy Orders in 1857, and was appointed chaplain and private secretary to his uncle, the Bishop of Tuam, a post he held for seven years
In 1858, he became rector of Kilmoyan and Cummer in County Galway. In 1864, he returned to Dublin as treasurer of St. Patrick’s Cathedral, Dublin.
He went on to serve as precentor at St. Patrick’s Cathedral (1869–76), Bishop of Meath (1876–84), and Archbishop of Dublin (1884).