John Cox Dillman Engleheart (1784–1862) was a miniature painter, the nephew of the miniature painter George Engleheart.
He entered his uncle's studio when he was but fourteen years of age. He first exhibited at the Royal Academy in 1801, and sent in altogether 157 works. He was a man of substantial means, and in his time a very popular painter, but his health broke down when he was forty-four years old, and he had to relinquish the pursuit of his profession. He lived at Tunbridge Wells for some years and died there in 1862.