| Statistic | Southwold | Ontario | National |
| Population | 4,540 | 14,804,681 | 38,134,230 |
| Population density (sq km) | 15 | 15 | 4 |
| Median age | 45.1 | 40.9 | 40.9 |
| Male/Female ratio | 1.0:1 | 1.0:1 | 1.0:1 |
| Married couples | 79% | 71% | 66% |
| Families w/ kids at home | 47% | 46% | 43% |
| Speak English only | 95.7% | 86.1% | 68.8% |
| Speak French only | 0.0% | 0.3% | 4.5% |
| Data | Percent |
| Black | 0.8% |
| South Asian | 0.7% |
| Chinese | 0.2% |
| Japanese | 0.2% |
| Southeast Asian | 0.2% |
| Data | Percent |
| United Kingdom | 2.1% |
| Netherlands | 1.7% |
| United States | 0.7% |
| Germany | 0.5% |
| Italy | 0.4% |