| Statistic | Markstay-Warren | Ontario | National |
| Population | 2,806 | 14,804,681 | 38,134,230 |
| Population density (sq km) | 5 | 15 | 4 |
| Median age | 48.9 | 40.9 | 40.9 |
| Male/Female ratio | 0.9:1 | 1.0:1 | 1.0:1 |
| Married couples | 67% | 71% | 66% |
| Families w/ kids at home | 35% | 46% | 43% |
| Speak English only | 53.6% | 86.1% | 68.8% |
| Speak French only | 1.5% | 0.3% | 4.5% |
| Data | Percent |
| South Asian | 1.6% |
| Filipino | 0.6% |
| Black | 0.3% |
| Latin American | 0.1% |
| Korean | 0.0% |
| Data | Percent |
| Brazil | 0.2% |
| Guyana | 0.1% |
| Philippines | 0.1% |
| Peru | 0.1% |
| Other Central America | 0.0% |