Le Mesnil-le-Roi is a commune in the Yvelines department in the Île-de-France region in north-central France. It is about 3.5 km from Saint-Germain-en-Laye. The name "Mesnil" comes from Latin: mansionilis meaning "little estate". The name "Le Mesnil-le-Roi" could be said "The King's small estate". On the other hand, the name of Mesnil-le-Roi in the time of the French Revolution was Le Mesnil-Carrières, "Mesnil quarries". The inhabitants are called Mesnilois and Mesniloise.