Parc départemental de l'Île-Saint-Denis, Urban park in L'Île-Saint-Denis, France

This green space sits along the Seine with wooded sections, walking paths, and open meadows for recreation and leisure. Different areas within the park provide varied landscapes and ways to spend time outdoors.

The park occupies the northern third of the Île-Saint-Denis, land the department began buying in 1971 when it was old market-garden plots turned into illegal dumps. Work started in 1981 and the last section opened in 1990. The Maison du parc burned in October 2021; its rebuilding, with a timber frame and larch cladding, was launched in October 2026.

The park's name echoes Alfred Sisley, the Impressionist painter, through the collège Alfred Sisley at its southern edge; the park itself was laid out from 1981 on former market-garden plots and wild dumps. Today it is a Natura 2000 site where visitors watch birds and mammals, and the Maison du parc, burned in October 2021, is being rebuilt with a larch-clad timber frame.

The park covers the northern third of the island, running 1.5 km from the Alfred Sisley school to the Épinay bridge; only the quai de la Marine borders it to the east. Facilities include two playgrounds (Olympe with water games, and Le Phare), a fitness area, a mini-tennis court, a football pitch, ping-pong and picnic tables, benches and a kiosk. The northern tip beyond the railway bridge is a nature reserve closed to the public.

The park is classed as a Natura 2000 zone, and the whole site up to the northern tip of the island and its banks forms part of a Zone naturelle d'intérêt écologique, faunistique et floristique. The northern point beyond the Épinay railway bridge holds a nature reserve closed to the public.