Carquefou (; Gallo: Carqefou, ) is a commune in the Loire-Atlantique, department in the region Pays de la Loire, in western France.
The headquarters of the geophysical research company Sercel is located in Carquefou.
In 2008, the local football team Union Sportive Jeanne d'Arc Carquefou reached the quarter-finals of the French Cup after a win over the 8-times national champions Olympique de Marseille on 19 March, putting the town in the national headlines.