James Adcock (1778 - April 30, 1860) was an English choral singer and director. He was a native of Eton, Berkshire. In 1786, he joined the choir of St. George's Chapel, Windsor, under Edward Webb and then Theodore Aylward Sr., and in Eton College Chapel under William Sexton. In 1797, he was appointed lay clerk in St. George's Chapel, and obtained a similar appointment at Eton two years later. He published several glees of his own composition, and The Rudiments of Singing, with about thirty solfeggi to assist persons wishing to sing at sight.