The couple signed their wedding contract on 8 June 1688. In a ceremony conducted by Pierre du Cambout de Coislin in the royal chapel of Versailles, Marie married Antonio Grimaldi, Duke of Valentinois on 13 June 1688. As part of the marriage contract, Louis XIV gave the House of Grimaldi the official rank of Foreign Princes at court. Her husband was the son and heir of Louis I, Prince of Monaco and Catherine Charlotte de Gramont, a former mistress of Louis XIV who had arranged the marriage between Marie and Antonio. Court gossips later stated that the match had been a scheme of Madame de Maintenon, who feared that if she did not remove Marie from court she would become mistress to the king. However Madame de Maintenon wrote that Marie was one of the most "likeable women in the kingdom". Saint-Simon described her in his Memoirs: "the duchesse de Valentinois was a charming young thing... spoilt by her parents' fondness for her and by the attentions of the courtiers who frequented the Lorraine household... who were its chief adornment attracted the most glittering young men. Her husband, very sensibly, realised he hadn't the upper hand", and Madame de La Fayette described her as "more of an elegant flirt than all of the ladies of the kingdom put together". Marie was sent to Monaco by her consort during his military service in 1692, where she was joined by her spouse some time later. There was a great scandal when she claimed that her father in law, the elderlyPrince Louis I, had made unwanted sexual advances towards her, possibly as a way to receive permission to return to Paris, which she did in 1693 and remained for the next four years; the couple returned to Monaco in 1697. After it was clear that Marie was not going to give birth to a son, her husband began a series of badly concealed affairs. Her husband fathered numerous illegitimate children during the marriage.
Princess of Monaco
At the death of her father-in-law, her husband succeeded to the principality of Monaco in 1701. She lived in Monaco with her consort until 1712 and their relationship was described as unhappy but peaceful. In reality, they lived apart; Antoine in the Giardinetto, a cottage he had built for his lover, Mademoiselle Montespan, and Marie in her pavilion, Mon Desert. Marie spent the last years of her life quietly, frequently returning to the French court. She died at the Prince's Palace in Monaco, having organised the marriages of her two surviving daughters, Louise Hippolyte and Margherita. She was buried at the Saint Nicholas Cathedral in Monaco. Her husband died in 1731 and was succeeded by their daughter Louise Hippolyte Grimaldi who became Princess of Monaco in her own right. She married Jacques Goyon, Count de Matignon and is a direct ancestress of the reigning Prince Albert II of Monaco.
Issue
Caterina Charlotte Grimaldi, Mademoiselle de Monaco died in infancy.