| Ontario to McHenry (Illinois) | 1,681.90 mi (2,706.76 km) |
| Ontario to McKeesport (Pennsylvania) | 2,107.01 mi (3,390.90 km) |
| Ontario to McKinleyville (California) | 594.64 mi (956.99 km) |
| Ontario to McKinney (Texas) | 1,204.05 mi (1,937.74 km) |
| Ontario to McLean (Virginia) | 2,251.63 mi (3,623.65 km) |
| Ontario to McMinnville (Oregon) | 826.61 mi (1,330.30 km) |
| Ontario to McMinnville (Tennessee) | 1,799.97 mi (2,896.78 km) |
| Ontario to McNair (Virginia) | 2,239.95 mi (3,604.85 km) |
| Ontario to McPherson (Kansas) | 1,149.02 mi (1,849.17 km) |
| Ontario to Mead Valley (California) | 23.27 mi (37.45 km) |
| Ontario to Meadow Woods (Florida) | 2,166.81 mi (3,487.15 km) |
| Ontario to Meadowbrook (Virginia) | 2,246.05 mi (3,614.67 km) |
| Ontario to Meadville (Pennsylvania) | 2,092.67 mi (3,367.83 km) |
| Ontario to Mebane (North Carolina) | 2,158.52 mi (3,473.81 km) |
| Ontario to Mechanicsville (Virginia) | 2,251.01 mi (3,622.64 km) |
