Landgravine Marie Louise of Hesse-Kassel (7 February 1688 – 9 April 1765) was a daughter of Charles I, Landgrave of Hesse-Kassel, and Maria Amalia of Courland. By her marriage to John William Friso, Prince of Orange, she became Princess consort of Orange, a title last held by Mary II of England. Like her husband, she is an ancestor 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, and of her young grandson, William V, Prince of Orange. She was often fondly referred to as Marijke Meu (Aunt Mary) by her Dutch subjects.

Marie Louise was one of seventeen children born to Charles I, Landgrave of Hesse-Kassel, by his wife and cousin, Maria Amalia of Courland. Two of her siblings included King Frederick I of Sweden and William VIII, Landgrave of Hesse-Kassel.

Marie Louise's paternal grandparents were William VI, Landgrave of Hesse-Kassel, and Hedwig Sophia of Brandenburg. Her maternal grandparents were Jacob Kettler, Duke of Courland, and Louise Charlotte of Brandenburg.

On 26 April 1709, Marie Louise was married to John William Friso, Prince of Orange. He was the eldest surviving son of Henry Casimir II, Prince of Nassau-Dietz, and Henriëtte Amalia of Anhalt-Dessau; he had inherited his title in 1702 from the childless William III, Prince of Orange, due to his descent from both William the Silent and Frederick Henry, Prince of Orange.

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