Claude Bouthillier, Sieur de Fouilletourte (1581 – 13 March 1652), French statesman, began his professional life as an advocate. In 1613 he was councillor in the Parlement of Paris, and in 1619 became councillor of state and a secretary to the queen-mother, Marie de Medici.
The connection of his father, Denis Bouthillier (died 1622), with Cardinal Richelieu secured for him the title of secretary of state in 1628, and he was able to remain on good terms with both Marie de Medici and Richelieu, in spite of their rivalry. In 1632 he became Superintendent of Finances. But his great role was in diplomacy.
Richelieu employed him on many diplomatic missions, and the success of his foreign policy was due in no small degree to Bouthillier's ability and devotion. In 1630 he had taken part at Regensburg in arranging the abortive treaty between the emperor and France. From 1633 to 1640 he was continually busied with secret missions in Germany, sometimes alone, sometimes with Father Joseph. Following Richelieu's instructions, he negotiated the alliances which brought France into the Thirty Years' War.
Meanwhile, at home, his tact and amiable disposition, as well as his reputation for straightforwardness, had secured for him a unique position of influence in a court torn by jealousies and intrigues. Trusted by the king, the confidant of Richelieu, the friend of Marie de Medici, and through his son, Leon, who was appointed in 1635 chancellor to Gaston d'Orléans, able to bring his influence to bear on that prince, he was an invaluable mediator; and the personal influence thus exercised, combined with the fact that he was at the head of both the finances and the foreign policy of France, made him, next to the cardinal, the most powerful man in the kingdom. Richelieu made him executor of his will, and Louis XIII named him a member of the council of regency which he intended should govern the kingdom after his death.