Louis Antoine war das zweite Kind der Madame de Montespan (1640-1707) aus ihrer Ehe mit Louis-Henri de Pardaillan de Gondrin (1640-1691). Nach der Trennung seiner Eltern wuchs er bei seiner Mutter auf. In ihren Memoiren lesen wir Folgendes über ihren Sohn: "The youthful Marquis d'Antin [Louis Antoine de Pardaillan de Gondrin] - my son - was growing up: the King showed him the most flattering signs of his attachment; and as the child had lived only with me, he dreaded his father's violent temper, of which he had often heard me speak. In order to have the custody of his son, the Marquis de Montespan had appealed to Parliament; but partisans of the King had shelved the matter, which, though ever in abeyance, was still pending. I had my son educated under my care, being sure of the tender attachment that would spring up between himself and the princes, his brothers. At the Montespan château, I admit, he would have learned to ride an unbroken horse, as well as to shoot hares, partridges, and big game; he would also have learned to talk loud, to use bad language, to babble about his pedigree, while ignorant of its history or its crest; in fine, he would have learned to despise his mother, and probably to hate her. Educated under my eyes, almost on the King's lap, he soon learned the customs of the Court and all that a well-born gentleman should know. He will be made Duc d'Antin, - I have the King's word for it ... The Procureur-Général caused a man from Béarn to be arrested, who had come to abduct my son. ..." (in: Memoirs of Madame la Marquise de Montespan – Being Historic Memoirs of the Court of Louis XIV., Volume 1, pp. 203-204). Sein Vater wollte nicht nur ihn, sondern auch seine Frau entführen lassen. Beides gelang ihm nicht.
Louis Antoine lebte nach der Trennung seiner Eltern bei seiner Mutter. Seinem Vater gelang es jedoch nach vielen Jahren, vom königlichen Gericht das Recht zu erhalten, seinen Sohn zu sich bringen zu lassen. Madame de Montespan schrieb hierzu: "M. de Montespan dared not come himself to Paris in order to execute the sentence [nämlich seinen Sohn zu sich zu holen]; he sent for that purpose two officers of artillery, his friends or relatives ... These gentlemen, having sent word to the father that the young d'Antin was my living image [er kam äußerlich ganz nach seiner Mutter, Madame de Montspan], he replied them, that they were to insist no longer, to abandon their mission, and to abandon a child who would never enjoy his favour since he resembled myself. Owing to this happy circumstance I was able to preserve my son." (in: Memoirs of Madame la Marquise de Montespan, Volume 2, p. 173).