Marguerite Louise d'Orléans, French princess (d. 1721)
Marguerite Louise d'Orléans (28 July 1645 – 17 September 1721) was a Princess of France who became Grand Duchess of Tuscany, as the wife of Grand Duke Cosimo III de' Medici.

Libertine and unruly in conduct from an early age, her relations with her husband and his family were tempestuous and often bitter, with repeated appeals for mediation to Louis XIV. Nevertheless, three children were born to the couple: Grand Prince Ferdinando, Anna Maria Luisa, Electress Palatine, and Gian Gastone.

In June 1675, five years after her husband had succeeded to the Grand Duchy and four years after the birth of their youngest child, Marguerite Louise and her husband separated and she retired with a pension to a convent on the outskirts of Paris. In France she proved little inclined to respect social conventions governing the life of a woman of her rank and proved a thorn in the side of the Tuscan authorities and the French monarchy, indulgent though it was.

In later life, she eventually adopted more conventional behaviour, took up pious works and even reformed the convent that became her second residence in the Paris suburbs. As the years went by she suffered serious setbacks to her health and the sadness of mourning her eldest son, Grand Prince Ferdinando, for whom she had had a genuine affection. Rendered financially independent by a legacy, she purchased a house in Paris, from which she spent the end of her life dispensing charity and keeping up dignified correspondence.