Marie Louise war das älteste Kind des Herzogs Philippe d'Orléans, des jüngeren Bruders des französischen Königs Ludwig XIV., und seiner ersten Gattin, Henriette Anna von England. Sie erblickte am 26. März 1662 [laut Cartwright Ady am frühen Morgen des 27. März] das Licht der Welt (in: Julia Mary Cartwright Ady: Madame, a life of Henrietta, daughter of Charles I. and Duchess of Orleans, id., p. 115]). Ihre Mutter hatte viele Fehlgeburten und eine Totgeburt im Jahr 1665, so dass Marie Louise nur zwei Vollgeschwister besaß: ihren Bruder Philippe Charles d'Orléans (1664-1666) und ihre Schwester Anne Marie d'Orléans (1669-1728), die Herzogin von Savoyen und Königin von Sizilien und Sardinien.
" ... at the early hour on the 27th [of March 1662], she [Henriette Anna] gave birth to a daughter. The event was premature, but passed off happily. Her mother [Henriette Maria von Frankreich] was with her at the time, and before six o'clock, the King and the two Queens [Anna von Spanien/Österreich und Maria Teresa von Spanien] arrived to offer Madame [Henriette Anna] their congratulations. Both parents, however, were greatly disappointed at the child's sex, and Madame, on hearing she had given birth to a daughter, is said to have exclaimed, 'Then throw her into the river!' Her mother-in-law was much scandalised at these lamentations, and by way of consoling Madame, observed that if she had not given birth to a prince, her little daughter, who was but a few months younger than the baby Dauphin, might some day yet become a Queen." (in: Julia Mary Cartwright Ady: Madame, a life of Henrietta, daughter of Charles I. and Duchess of Orleans, id., p. 115).
"It was this one [Marie Louise] whom Monsieur [ihr Vater Philippe I.] destined in his own mind for Monseigneur le Dauphin; and the Princess, accustomed early to this prospect, had insensibly adapted to it her mind and hope. Young, beautiful, agreeable and charming as her mother, she created already the keenest sensation at Court, and the King [Ludwig XIV.] felt an inclination to cherish her as much as he had loved Madame [Marie Louises Mutter Henriette Anna]. But the excessive freedom which this alliance would not have failed to give his brother ... prevented His Majesty from giving way to his penchant for Marie Louise. On the contrary, he consented to her marriage with the King of Spain, and the news of it was accordingly carried to Monsieur le Duc d'Orléans. He and his wife [seine zweite Gattin Liselotte von der Pfalz] felt much annoyance at it. ... Monsieur conveyed the news to his beloved daughter, and, on hearing that she was to be made Queen of Spain, this amiable child uttered loud lamentations. When she went to Versailles to thank the King, her uncle, her fine eyes were still suffused with tears. The few words which she uttered were mingled with sighing and weeping; and when she saw the indifference of her cousin, who felicitated her like the rest, she almost fainted with grief and regret. ... Marie Louise, having been married by proxy, in the great Chapel of Saint-Germain, where the Cardinal de Bouillon blessed the ring in his quality of Grand-Almoner of France, left for that Spain which her young heart distrusted. Her beauty and charms rendered her precious to the Monarch [Karl II. von Spanien], utterly melancholy and devout as he was. He did not delay subjecting her to the wretched, petty, tiresome and absurd etiquette of that Gothic Court. Mademoiselle submitted to all these nothings, seeing she had been able to submit to separation from France. She condemned herself to the most fastidious observances and the most sore privations, which did not much ameliorate her lot." (in: Memoirs of Madame la Marquise de Montespan, Volume 2, pp. 74-77).
Nach dem frühen Tod ihrer Mutter, Henriette Anna von England, der Herzogin von Orléans, am 30. Juni 1670 lebte sie bei ihrem Onkel und dessen Gattin, dem französischen König Ludwig XIV. und Maria Teresa von Spanien, und wurde zusammen mit ihrem Cousin, dem Dauphin Ludwig, erzogen, bis ihr Vater im Jahr 1671 erneut heiratete. "Contemporaries describe [von Marie Louise] the bright eyes and arched brows, the rosy lips and chestnut hair that recalled her dead mother [Henriette Anna]. ... None of all the Royal children was so great a favourite at Court, no one blushed so prettily or laughed so merrily. ... [ihr Vater] had already made up his mind that his daughter should marry the Dauphin. They had been companions from childhood and, as they grew up, they played and danced together. Marie Louise was the Dauphin's partner at every ball and fête, and he took the greatest pleasure in her company. But such a marriage did not suit the policy of Louis XIV. He had made up his mind that Mademoiselle should marry Charles II., the feeble and imbecile King of Spain, and the poor young Princess was sacrificed to his ambitious plans. In vain she threw herself at her uncle's feet, and begged to be allowed to remain in France. Louis was inflexible. ... The marriage was celebrated with great pomp at Fontainebleau, in May 1679, and Monsieur's [Marie Louises Vater] thoughts were too much absorbed in the jewels he wore on his coat, to heed his daughter's tears." (in: Julia Mary Cartwright Ady: Madame, a life of Henrietta, daughter of Charles I. and Duchess of Orleans, id., pp. 395-396).
"Marie Louise was a spoilt beauty of the most refined and gayest court in Europe. She had when she was a child lost her mother; but everybody was in love with her, from Louis XIV. downward; and it had long been understood that she might marry the Dauphin [Louis], with whom she was on the tenderest terms of affection. ... She and the Dauphin were deeply in love with each other, and had been so since childhood. ... When her father and afterwards her uncle gravely told her the honour that was in store for her, she implored them in an agony of passionate tears to save her from such a fate. To her stepmother, to the Queen Marie Theresa, to the king, she appealed on her knees, again and again, to let her stay in France, where she was so happy, and not to send her far away amongst people she did not love. She was told that her duty was to France." (in: Martin Hume: Queens of Old Spain. London 19112, pp. 415-416).
"Die arme Marie-Louise nahm in ihrer Kutsche [als sie Frankreich verließ] ihre beiden Lieblingshündchen mit, die in Madrid die einzigen französischen Gefährten sein sollten, die man ihr gestattete. Madame [ihre Stiefmutter Liselotte von der Pfalz] brachte ein wenig Licht in ihre Abgeschiedenheit, indem sie ihr getreulich schrieb, zweimal pro Woche, und das zehn Jahre lang. Von den Tausenden von Briefen, die sie geschrieben haben muß, ist uns nicht ein einziger erhalten geblieben. Marie-Louise beantwortete im allgemeinen jeden dieser Briefe: 'Ich griche all woche brieff von unßerer königin in Spanien', schreibt Madame 1682 an Karllutz [ihren Halbbruder]." (in: Dirk Van der Cruysse: „Madame sein ist ein ellendes Handwerk“: Liselotte von der Pfalz – eine deutsche Prinzessin am Hof des Sonnenkönigs, S. 271).