Marie Louise of Hesse-Kassel was a Dutch regent, Princess of Orange by marriage to John William Friso, Prince of Orange, and regent of the Netherlands during the minority of her son and her grandson. She was a daughter of Charles I, Landgrave of Hesse-Kassel, and Maria Amalia of Courland. She and her husband are the most recent common ancestors of all currently reigning monarchs in Europe.
Marie Louise is notable for having served as regent for two periods in Dutch history: during the reigns of her young son, William IV, Prince of Orange from 1711 and 1730, and of her young grandson, William V, Prince of Orange, from 1759 to 1765. She was often fondly referred to as Marijke Meu by her Dutch subjects.