Henri du Plessis-Guénégaud, Lord of the Plessis-Belleville, Marquis de La Garnache[1] (1610 – 16 March 1676) was a French scholar and a Secretary of State during the reigns of Louis XIII and Louis XIV.

[2] In 1643, he became Secretary of State of several regions of France, including Paris, the Maison du Roi, and ecclesiastical affairs.

He supported Anne d'Autriche during the Fronde and was made Garde des Sceaux in 1656, but was disgraced in 1669, when he was succeeded as Secretary of State by Jean-Baptiste Colbert.

[2] Their children included: He was the brother of Claude's treasurer, brother-in-law of César d'Albret who married his sister Madeleine.

[2] He and his wife, who were known for their Jansenist sympathies, held a famous salon at their hôtel on the Quai de Nevers.