Richard Reader Harris, K.C. (1847 – 25 March, 1909) was a prominent English barrister, King's Counsel and Master of the Bench of Gray's Inn, who was also a Methodist minister, founder of the Pentecostal League of Prayer, and author of 34 Christian books. He is particularly remembered as an advocate of British Israelism, the belief that people of Western European descent are also the direct lineal descendants of the Ten Lost Tribes.
He started his career as a civil engineer for the Great Western Railway (GWR) and Great Eastern Railway (GER), before taking a post as chief engineer to the Republic of Bolivia. On his return to London in 1883 he trained for the bar, and was called at Gray's Inn, where he was later elected to the Bench.
Reader Harris drifted from the liberal view of Christianity of his teens to join Charles Bradlaugh's Ethical Society. Bradlaugh, an atheist, mocked Christians who lived immoral lives while he lectured on Bible texts and advocated that his audience abide by ideas expressed in the Sermon on the Mount. As a member of the Puritan wing of Bradlaugh’s Ethical Society, Harris pledged not to smoke or drink.