| Statistic | Lac-Sergent | Quebec | National |
| Population | 520 | 8,565,732 | 38,134,230 |
| Population density (sq km) | 140 | 6 | 4 |
| Median age | 50.0 | 42.6 | 40.9 |
| Male/Female ratio | 1.0:1 | 1.0:1 | 1.0:1 |
| Married couples | 53% | 50% | 66% |
| Families w/ kids at home | 34% | 40% | 43% |
| Speak English only | 0.0% | 4.7% | 68.8% |
| Speak French only | 58.8% | 49.5% | 4.5% |
| Data | Percent |
| N/A | 0.0% |
| Data | Percent |
| United States | 3.3% |
| France | 2.0% |
| Other Eastern Europe | 0.8% |
| Chile | 0.2% |
| China | 0.2% |