The Counts of Dreux were a noble family of France, who took their title from the chief stronghold of their domain, the château of Dreux, which lies near the boundary between Normandy and the Île-de-France. They are notable for inheriting the Duchy of Brittany through Pierre de Dreux's marriage to Alix de Thouars in the early 13th century.

In the tenth century the lands belonged to the forebears of the Capetians; they passed by marriage to Walter, Count of the Vexin, then to Richard I of Normandy. In 1017 the lands were given as dowry to Richard's illegitimate daughter Matilda, who married Odo II, Count of Blois.

King Robert II of France confiscated the lands of Dreux from Odo, and they formed part of the royal domain until Louis the Fat granted the county of Dreux as an appanage to his son Robert. The descendants of Robert held the county of Dreux until 1355, when the heiress, Countess Joan II of Dreux, married Simon de Thouars. Simon and Joan had three daughters and no sons; their daughters sold their interests in the county of Dreux to King Charles VI.

King Charles gave the county of Dreux as a dowry in the marriage of his kinswoman Marguerite de Bourbon, daughter of Peter, Duke of Bourbon and of Isabella de Valois, daughter of Charles of Valois, with Arnaud-Amanieu d'Albret in 1382. The county returned to the crown in 1556, and thereafter formed part of the royal domain, then the lands of François, Duke of Anjou, and after his death was sold to the Duke of Nemours. It returned to the royal domain in the reign of Louis XV.