| Statistic | Longueuil | Quebec | National |
| Population | 249,920 | 8,565,732 | 38,134,230 |
| Population density (sq km) | 2,158 | 6 | 4 |
| Median age | 41.7 | 42.6 | 40.9 |
| Male/Female ratio | 1.0:1 | 1.0:1 | 1.0:1 |
| Married couples | 49% | 50% | 66% |
| Families w/ kids at home | 39% | 40% | 43% |
| Speak English only | 2.7% | 4.7% | 68.8% |
| Speak French only | 46.6% | 49.5% | 4.5% |
| Data | Percent |
| Black | 8.9% |
| Arab | 3.8% |
| Latin American | 3.7% |
| Chinese | 1.6% |
| Southeast Asian | 1.2% |
| Data | Percent |
| Haiti | 1.7% |
| Morocco | 1.3% |
| Algeria | 1.3% |
| France | 1.2% |
| Colombia | 0.7% |