Assigned to the Atlantic Fleet, Melville reported to Newport, in January 1916. On 11 May 1917, a month after the United States entered World War I, the destroyer tender got underway for Queenstown, Ireland, arriving on the 22nd. She carried out repair and support operations and served as flagship for Vice Admiral William Sims, Commander of U.S. Naval Forces in European waters, from 10 September until 4 January 1919.