Isabella Hill (1 April 1833 – 6 June 1879), better known as Mrs Howard Paul, was an English actress, operatic singer and actress-manager of the Victorian era, best remembered for creating the role of Lady Sangazure in the Gilbert and Sullivan comic opera The Sorcerer (1877).
Her stage career began in 1853 in London in ballad operas, such as The Beggar's Opera. In 1854 she married the American writer Henry Howard Paul, in whose comic entertainments the two performed for much of the next two decades, often on tour, both in Britain and America. She was popular for her musical impersonations of singers of the day. She also played in Victorian burlesque and other theatrical roles, among the best known of which was her Lady Macbeth at the Theatre Royal, Drury Lane in 1869. Various composers wrote songs for her to premiere.
After The Sorcerer, Gilbert and Sullivan cast Mrs Paul in their next opera, H.M.S. Pinafore, but her vocal abilities had declined so much by that point that they cut parts of her role, and she resigned from the production.