L'Aiguillon-sur-Mer (, literally L'Aiguillon on Sea) is a former commune in the Vendée department in western France. It was merged with La Faute-sur-Mer to form L'Aiguillon-la-Presqu'île on 1 January 2022.
The river Lay forms all of the commune's northwestern border, then flows into the Atlantic Ocean, which forms all of its western border.