Plaisir is a commune situated in the heart of the Yvelines department within the Île-de-France region of northern France. It is positioned in the western outer suburbs of Paris, located approximately 29.5 km (18.3 mi) from the city center.
The commune shares borders with several neighboring municipalities, including Élancourt to the south, Trappes to the southeast, and Les Clayes-sous-Bois to the east.