Reginald Fleming Johnston(1874~1938) was the teacher of Pu Yi, the last Emperor of China, and later appointed as commissioner of British-held Weihaiwei.

Born in Edinburgh, Scotland, he studied at University of Edinburgh and later Magdalen College, Oxford. In 1898, he entered into colonial service and worked in Hong Kong. In 1919, he was elected as tutor of thirteen-years-old Puyi who still lived in the Forbidden City at Beijing. Puyi was expelled from the Old Palace in 1924 when Johnston returned to Britain and became professor of Chinese at University of London. In 1926, he was appointed as commissioner of Weihaiwei leased territory in Shandong Province. He ruled the colony like a Chinese mandarin until Weihaiwei was returned to the Nationalist Government in Nanjing on October 1, 1930.

He retired to return to Scotland and lived at a small island of Eilean Righ in Loch Graignish . He died in Edinburgh.

He was portrayed by Peter O'Toole in Bernardo Bertolucci's film dramatization of Pu Yi's life The Last Emperor.