Gif-sur-Yvette is a commune in southwestern Île-de-France, France. It is located in the Vallée de Chevreuse, 22.9 km from the centre of Paris…Gif-sur-Yvette is a commune in southwestern Île-de-France, France. It is located in the Vallée de Chevreuse, 22.9 km from the centre of Paris, in the Essonne department on the departmental border with Yvelines. In 2021, it had a population of 22,352.