| Statistic | Saint-Thomas | Quebec | National |
| Population | 3,364 | 8,565,732 | 38,134,230 |
| Population density (sq km) | 35 | 6 | 4 |
| Median age | 42.8 | 42.6 | 40.9 |
| Male/Female ratio | 1.0:1 | 1.0:1 | 1.0:1 |
| Married couples | 48% | 50% | 66% |
| Families w/ kids at home | 39% | 40% | 43% |
| Speak English only | 0.2% | 4.7% | 68.8% |
| Speak French only | 78.8% | 49.5% | 4.5% |
| Data | Percent |
| Black | 0.9% |
| West Asian | 0.4% |
| Southeast Asian | 0.3% |
| Arab | 0.1% |
| Korean | 0.0% |
| Data | Percent |
| Haiti | 0.3% |
| France | 0.2% |
| Iran | 0.1% |
| Other Western Europe | 0.1% |
| Colombia | 0.0% |