| Statistic | Thornlea | Markham | Ontario |
| Population | 5,179 | 359,111 | 14,804,681 |
| Population density (sq km) | 1,675 | 1,675 | 15 |
| Median age | 50.9 | 40.7 | 40.9 |
| Male/Female ratio | 1.0:1 | 1.0:1 | 1.0:1 |
| Married couples | 91% | 82% | 71% |
| Families w/ kids at home | 57% | 58% | 46% |
| Speak English only | 86.6% | 84.1% | 86.1% |
| Speak French only | 0.1% | 0.0% | 0.3% |
| Data | Percent |
| Chinese | 40.6% |
| South Asian | 12.8% |
| West Asian | 7.1% |
| Korean | 2.7% |
| Arab | 1.6% |
| Data | Percent |
| China | 14.7% |
| Hong Kong | 7.7% |
| Iran | 5.5% |
| South Africa | 3.7% |
| India | 3.1% |