Chatelain may refer to:

• Châtelain, the French equivalent of the English castellan, i.e. the commander of a castle
• Chatelain (surname)
• Châtelain, Mayenne,s a commune in the Mayenne department in north-western France
• Camblain-Châtelain, a commune in the Pas-de-Calais department in the Nord-Pas-de-Calais region of France
• Lignières-Châtelain, a commune in the Somme department in Picardie in northern France
• USS Chatelain (DE-149), a destroyer escort built for the U.S. Navy during World War II

Châtelain (Med. Lat. castellanus, from castellum, a castle) was originally merely the French equivalent of the English castellan, i.e. the commander of a castle.