French general who distinguished himself against the Spanish and in the civil wars of the Fronde (Fronde, the) (1648–53), which began as an uprising of the members of the Parlement of Paris against royal absolutism.

Nicknamed “Cadet la Perle” because he was the youngest of his family and because he wore a pearl in his ear, Harcourt fought in the wars against Spain in Catalonia, Flanders, Italy, and France, as well as in Louis XIII's campaigns against the Huguenots (1621–28). Perhaps his most famous accomplishment was the taking of Turin after a three-month siege (1640). In 1643 he was made master of the horses by King Louis XIII.

When the Fronde broke out, Harcourt sided with the crown. He conducted Louis XIV to Normandy, where he succeeded in making the young king's authority respected. In 1651 he lifted the siege of Cognac and assured the obedience of Guyenne.

Finding that he was poorly rewarded for his services, Harcourt seized several towns in Alsace. Obliged to withdraw by Henri, Duke de La Ferté-Senneterre, he made peace with the French court and settled down as governor of Anjou.