De Monroyde Monroy is a surname of Spanish origin. This habitational name derived from de meaning "of" & Monroy, meaning "red mountain". A place in the Province of Cáceres, Spain.Notable people with the surname include: Hernán Cortés de Monroy y Pizarro, Spanish conquistador Rodrigo de Monroy y Almaraz, 5th Lord of Monroy, Spanish nobleman