John Emms was born in Norfolk, son of the amateur artist Henry William Emms. He went to London and became a studio assistant to Frederic, Lord Leighton. Emms helped Leighton paint the fresco of The Ten Virgins at Lyndhurst Parish Church in Hampshire, and later moved to Lyndhurst himself. He was drawn to the New Forest as he was a keen huntsman. From 1866 onwards, Emms was a frequent exhibitor at the Royal Academy. His main subjects were dogs and horses, and his work displays considerable precision and talent. He was admired for the vitality of his animals and was in demand across the country as an animal portraitist. In 1881 he built a large house and studio at Lyndhurst, where he remained for the rest of his life.