Poissy is a rail station in Poissy, France, at the western edge of Paris. Although interconnected with the Paris Métro, it is actually located on the RER A line, one of the five lines of the Réseau Express Régional, or Regional Express Network. The station is also served by the SNCF (Société Nationale des Chemins de fer Français), France's national railway. It is situated on the Paris–Le Havre railway.