The canton Grande-Synthe has 13 communes.
| Code | Name | Population ▼ |
|---|---|---|
| 59271 | Grande-Synthe | 20 239 |
| 59273 | Gravelines | 11 430 |
| 59094 | Bourbourg | 6 931 |
| 59359 | Loon-Plage | 5 952 |
| 59272 | Grand-Fort-Philippe | 4 887 |
| 59110 | Brouckerque | 1 452 |
| 59358 | Looberghe | 1 228 |
| 59130 | Cappelle-Brouck | 1 169 |
| 59463 | Pitgam | 1 007 |
| 59539 | Saint-Pierre-Brouck | 989 |
| 59159 | Craywick | 791 |
| 59532 | Saint-Georges-sur-l'Aa | 287 |
| 59182 | Drincham | 281 |