Gometz-le-Châtel () is a commune in the Essonne department of France. It is a southern suburb of Paris, 25 km from the center of Paris.
This village is near Les Ulis, Bures-sur-Yvette, Gif-sur-Yvette and Gometz-la-Ville, along the old road from Paris to Chartres, crossing the Hurepoix.
Gometz-le-Châtel has an oceanic climate (Köppen climate classification Cfb). The average annual temperature in Gometz-le-Châtel is . The average annual rainfall is with December as the wettest month. The temperatures are highest on average in July, at around , and lowest in January, at around . The highest temperature ever recorded in Gometz-le-Châtel was on 25 July 2019; the coldest temperature ever recorded was on 16 January 1985.
Inhabitants of Gometz-le-Châtel are called Castelgometziens in French.