Uchter John Mark Knox, 5th Earl of Ranfurly GCMG GCStJ PC (Ire) JP DL (14 August 1856 – 1 October 1933), was a British politician and colonial governor. He was Governor of New Zealand from 1897 to 1904.
Ranfurly served as a Lord-in-Waiting under Lord Salisbury between 1895 and 1897 and was knighted as a Knight Commander of the Order of St Michael and St George (KCMG) in 1897 for his public services. He was appointed to succeed The Earl of Glasgow as Governor of New Zealand on 6 April 1897, assuming office on 10 August. Lord Ranfurly became Honorary Colonel of the 1st Wellington Battalion (1898) and of the 1st South Canterbury Mounted Rifles (1902). He was created a Knight Grand Cross of the Order of St Michael and St George (GCMG) in June 1901, on the occasion of the visit of TRH the Duke and Duchess of Cornwall and York (later King George V and Queen Mary) to New Zealand. His term ended on 19 June 1904, when he personally handed over office to Lord Plunket. He is remembered for his donation of the Ranfurly Shield, a New Zealand sporting trophy.
On his return to England Ranfurly was made an Irish Privy Counsellor (1905); then for a time he returned to farm in Mildura, Victoria, Australia. But he soon devoted more and more time to his other great interest, the Order of St. John of Jerusalem. In 1914 he was a Knight of Justice, and Registrar of the Order in London, becoming (1915–19) Director of its Ambulance Department. In 1919 the French Government made him an Officer of the Legion of Honour for his services in this connection during the war.
After the partition of Ireland, Lord Ranfurly was made a Privy Counsellor for Northern Ireland in 1923, also serving as Deputy Lieutenant and Justice of the Peace for his family's native County Tyrone. He continued his association with the Order of St. John, becoming Bailiff Grand Cross in 1926.
Lord Ranfurly died on 1 October 1933, aged 77, and was succeeded by his grandson, Daniel Knox, 6th Earl of Ranfurly.