Sir Percy Lyham Loraine, 12th Baronet GCMG PC (5 November 1880 – 23 May 1961) was a British diplomat. He was British High Commissioner to Egypt from 1929 to 1933, British Ambassador to Turkey from 1933 to 1939 and British Ambassador to Italy from 1939 to 1940. In later life he was involved in breeding thoroughbreds for horse racing and won the 2000 Guineas Stakes in 1954 with Darius. He was the last of the Loraine baronets, having no sons to succeed him.
Loraine was born in London on 5 November 1880 the second son of Admiral Sir Lambton Loraine, the 11th Baronet and his wife Frederica Mary née Broke. Educated at Eton College from 1893 until 1899 when he went to New College, Oxford. In 1899 at the start of the Second Boer War he joined the Imperial Yeomanry and served on active duty in South Africa until 1902. In 1904, he joined the diplomatic service.
He first served in the Middle East, at the British missions in Istanbul and Tehran, where he was Envoy Extraordinary and Minister Plenipotentiary 1921-26, before being posted in Rome, Beijing, Paris and Madrid. He took part in the 1919 Paris Peace Conference which was held following the end of World War I, before being sent as minister in Tehran and then Athens.