| Statistic | Wellesley | Ontario | National |
| Population | 12,358 | 14,804,681 | 38,134,230 |
| Population density (sq km) | 43 | 15 | 4 |
| Median age | 34.4 | 40.9 | 40.9 |
| Male/Female ratio | 1.0:1 | 1.0:1 | 1.0:1 |
| Married couples | 88% | 71% | 66% |
| Families w/ kids at home | 59% | 46% | 43% |
| Speak English only | 92.9% | 86.1% | 68.8% |
| Speak French only | 0.1% | 0.3% | 4.5% |
| Data | Percent |
| South Asian | 1.0% |
| Filipino | 0.6% |
| Latin American | 0.5% |
| Southeast Asian | 0.4% |
| Chinese | 0.3% |
| Data | Percent |
| Mexico | 1.9% |
| United Kingdom | 0.9% |
| Germany | 0.5% |
| Romania | 0.4% |
| United States | 0.3% |