| Statistic | Saint-Marc-sur-Richelieu | Quebec | National |
| Population | 2,239 | 8,565,732 | 38,134,230 |
| Population density (sq km) | 36 | 6 | 4 |
| Median age | 45.0 | 42.6 | 40.9 |
| Male/Female ratio | 0.9:1 | 1.0:1 | 1.0:1 |
| Married couples | 45% | 50% | 66% |
| Families w/ kids at home | 43% | 40% | 43% |
| Speak English only | 0.2% | 4.7% | 68.8% |
| Speak French only | 58.7% | 49.5% | 4.5% |
| Data | Percent |
| Chinese | 1.0% |
| Latin American | 0.6% |
| Southeast Asian | 0.1% |
| N/A | 0.0% |
| Data | Percent |
| France | 1.4% |
| China | 0.7% |
| Vietnam | 0.3% |
| Mexico | 0.1% |
| El Salvador | 0.1% |