Jacques Goÿon de Matignon (Jacques François Léonor) was Count of Thorigny, Prince of Monaco as Jacques I, and the fourth Duke of Valentinois from 1731 until 1733.
Jacques came from an ancient Norman family. "Thorigny" is now called Torigni-sur-Vire, where the Mairie is the former family chateau. His uncle was Marshal Charles Auguste de Goÿon de Matignon.
He was a son of Jacques Goÿon de Matignon, jure uxoris Comte de Thorigny, and Charlotte Goyon de Matignon, Comtesse de Thorigny suo jure.
When Antonio I of Monaco and his wife Marie de Lorraine-Armagnac was looking for a consort for his daughter and heir Louise Hippolyte of Monaco, the family proposed him as a candidate. His candidacy was supported by King Louis XIV of France, who wanted to solidify French influence in Monaco. Jacques and Louise Hippolyte married on 20 October 1715 and had nine children. The wedding ceremony was the first official act that the five-year-old king, Louis XV, carried out during the Regency of Philippe II, Duke of Orléans.
At the end of 1731, Louise Hippolyte died of smallpox. Jacques I neglected the affairs of state and, under pressure from the population, had to leave the country in May 1732. He abdicated in favor of his son Honoré the next year. His Paris residence was named after him Hôtel Matignon and is today the official residence of the Prime Minister of France.