Colline d'Élancourt, Mountain peak in Yvelines, France.

The Colline d'Élancourt is a hill in Yvelines reaching 231 meters high and the highest elevation point in the Île-de-France region. On clear days, visitors can spot the Eiffel Tower, Montparnasse Tower, and the La Défense business district on the horizon.

The site was a millstone quarry from 1881, worked by Italian masons Joseph Marzi brought from Giaveno between 1920 and 1930; the Marzi firm closed in 1959 as concrete replaced millstone. After World War II the quarry became a landfill for Versailles, Saint-Cyr, Trappes and Bois-d'Arcy, covering 59 hectares by 1972 and closing in 1974. The hill was then built up with spoil from the Saint-Quentin-en-Yvelines new town and reached its present height in 1992.

The name La Revanche appears in the 1881 land register, and the municipal council renamed the hill Colline d'Élancourt in 2004. Quarrymen from La Maddalena di Giaveno in Piedmont settled here from 1920; their descendants founded an association in 1987 and return to the village each year. Graves of some of these quarrymen lie in Élancourt cemetery.

The main entrance is on the east side, on avenue Jean-Pierre Timbaud in Trappes; from there a paved road leads directly and easily to the summit. Further entrances lie on rue Alain Colas and chemin de la Julienne in Élancourt. The whole hill stands south of the D 912, near the Clef de Saint-Pierre district.

The 2024 Olympic mountain bike course was designed by Nick Floros and built specifically for the Games, with races held on 28 and 29 July 2024. The hill had already hosted La Revancharde, a VTT challenge counting over 200 participants for more than 20 years.