Grande-Synthe (French pronunciation: [ɡʁɑ̃d sɛ̃t]; West Flemish: Groot-Sinten) is a commune in the Nord department in the Nord-Pas de Calais region in northern France.

[3] It is the third-largest suburb of the city of Dunkerque (Dunkirk) and lies adjacent to it on the west.

In 1980, a large part of Petite-Synthe was detached from Dunkerque and included in Grande-Synthe.

Grande-Synthe is twinned with:

This Nord geographical article is a stub.