Châteaufort (French pronunciation: [ʃɑtofɔʁ]) is a commune in the Yvelines department in Île-de-France in north-central France. It is located 9 km (5.6 mi) south of Versailles, and 27 km (17 mi) southwest of Paris.

Châteaufort inhabitants are named Castelfortain.

The commune is named after the existence of three fortified castles during the Middle Ages; indeed, château fort means "fortified castle" in French.

On August 19, 1913, ahead of the Châteaufort aerodrome, the French aviator Adolphe Pégoud became the first man to jump from a plane using a parachute. The jump was made from a Blériot plane 200 m above the ground.

In the 20th century, Farman Aviation Works was headquartered in Châteaufort.

• Communes of the Yvelines department