John Patrick Crichton-Stuart, 3rd Marquess of Bute, KT (12 September 1847 – 9 October 1900) was a landed aristocrat, industrial magnate, antiquarian, scholar, philanthropist, and architectural patron.
Succeeding to the marquisate at the age of only six months, his vast inheritance reportedly made him the richest man in the world. His conversion to Catholicism from the Church of Scotland at the age of 21 scandalised Victorian society and led Prime Minister Benjamin Disraeli to use the Marquess as the basis for the eponymous hero of his novel Lothair, published in 1870. Marrying into one of Britain's most illustrious Catholic families, Bute became one of the leaders of the British Catholic community. His enormous expenditure on building and restoration made him the foremost architectural patron of the 19th century.
Lord Bute died in 1900, at the age of only 53; his heart was buried on the Mount of Olives in Jerusalem. He was a Knight Grand Cross of the Holy Sepulchre, Knight of the Order of St. Gregory the Great and Hereditary Keeper of Rothesay Castle.