| 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% |