The Countess of Hainaut was a noble title held by the female rulers of the historical region of Hainaut in present-day Belgium and France. This title was often associated with the ruling families of the County of Hainaut, which played a significant role in medieval European politics and alliances. Throughout history, several notable women held the title, influencing local governance and regional affairs. The Countess often acted as a regent or co-ruler alongside her husband, the Count, and was involved in the administration of the county, contributing to its cultural and economic development.