John Henry Chapman was a Church of England clergyman who converted to Catholicism and became a barrister. Educated at Pembroke College, Oxford, he graduated MA. He was ordained an Anglican priest and appointed a curate before converting to the Roman Catholic church. He subsequently trained in law, and was called to the bar at the Inner Temple. He was a Fellow of the Society of Antiquaries of London. In 1888 he was resident at North Kensington, and was elected to the London School Board as one of the representatives of the Chelsea Division. He served a single term on the board, retiring in 1891.