Marchioness of Hertford is the title given to the wife of the Marquess of Hertford. The title has been held by several women, including:
Isabella Ingram-Seymour-Conway, Marchioness of Hertford (1759-1834) Maria Seymour-Conway, Marchioness of Hertford (1771-1856) Emily Seymour, Marchioness of Hertford (1816-1902) Mary Seymour, Marchioness of Hertford (1846-1909)