Gareth Hughes was born William John Hughes on 23 August 1894 in Dafen, near Llanelli, Carmarthenshire, into a working-class Welsh family. He developed a love of theatre as a child and, at the age of sixteen, left home for London to pursue an acting career, adopting the stage name Gareth Hughes.
He worked with several UK touring repertory companies before becoming involved in a movement to promote Welsh national drama. In 1914 he sailed to New York with the Welsh Players to perform J. O. Francis's play Change at the Booth Theatre, and when his fellow actors returned home that May, Hughes chose to remain in America.
By the end of 1915 he had become a Broadway success, and film offers followed. His early screen work included Eyes of Youth (1919) with Clara Kimball Young and Mrs. Wiggs of the Cabbage Patch (1919) with Marguerite Clark. He signed with Metro Pictures and won his best-remembered role in Sentimental Tommy (1921), personally selected for the part by author J. M. Barrie. He went on to make forty-five films between 1918 and 1931, usually cast as a sensitive, callow leading man.
Hughes lost his fortune in the 1929 Wall Street Crash and returned to the stage, his final role being Shylock in The Merchant of Venice at the Hollywood Playhouse in 1938. In the early 1940s he experienced a religious calling, took the name Brother David, and in 1944 became a Christian missionary to the Paiute people of the Pyramid Lake Reservation in Nevada, where he spent almost fourteen years.
In 1958 Hughes returned to Llanelli to spend his final years, but he missed the Californian climate and went back to the United States after five months. He later moved into the Motion Picture Country Home in Woodland Hills, California, where he died on 1 October 1965. He is remembered in Llanelli today with a bronze plaque at Parc Howard Museum and a blue plaque at his boyhood home on Princess Street.