During the Middle Ages, the city profited from the Champagne fairs, markets for leather, cloth, spices, and other goods.

Then, the Valois and the town of Crépy-en-Valois were annexed by the monarchy, and administration was given to a member of the royal family.

On 1 September 1914, the 13th Infantry Brigade of 5th Division, part of the British Expeditionary Force, fought a rearguard action here against the advancing German Army, during the Retreat from Mons.

[3] The population of the town increased after World War II, because Crépy is located near Paris (64 km or 40 mi).

Crépy-en-Valois was deeply affected by the 1982 Beaune coach crash, in which 44 local children died.