Earl of Ranfurly, of Dungannon in the County of Tyrone, is a title in the Peerage of Ireland. It was created in 1831 for Thomas Knox, 2nd Viscount Northland. He had earlier represented County Tyrone in the House of Commons, and had already been created Baron Ranfurly, of Ramphorlie in the County of Renfrew, in the Peerage of the United Kingdom in 1826. Knox was the eldest son of Thomas Knox, who represented Dungannon in the Irish House of Commons. He was created Baron Welles, of Dungannon in the County of Tyrone, in 1781, and Viscount Northland, of Dungannon in the County of Tyrone, in 1791. Both titles were in the Peerage of Ireland. Lord Northland also sat in the British House of Lords as one of the 28 original Irish Representative Peers.
The first Earl was succeeded by his son, the second Earl. He sat as Member of Parliament for County Tyrone and Dungannon. His son, the third Earl, also represented Dungannon in Parliament. On his early death in 1858, having held the titles for only two months, the peerages passed to his eight-year-old son, the fourth Earl. He also died young and was succeeded by his younger brother, the fifth Earl. He served as a Lord-in-Waiting (government whip in the House of Lords) in the third Conservative administration of Lord Salisbury and was Governor of New Zealand between 1897 and 1904. He also was a member of The Apprentice Boys of Derry Parent Club in Londonderry.