Sir William Parsons, 4th Baronet of Birr Castle (6 May 1731 – 1 May 1791) was an Irish politician and baronet.
He was the son of Sir Laurence Parsons, 3rd Baronet and Mary Sprigge. From 1757 until his death in 1797, Parsons served as member of parliament (MP) in the Irish House of Commons for King's County. He was High Sheriff of King's County in 1779.
Marriage and children
He married Mary Clere, daughter of John Clere, on 28 June 1754. Laurence Parsons, 2nd Earl of Rosse (21 May 1758 – 24 February 1841) John Clere Parsons (1760–1826) Reverend William Parsons (1764–1838) Thomas Clere Parsons (1766–1825)