| Ontario to Mendota (California) | 244.07 mi (392.79 km) |
| Ontario to Mendota Heights (Minnesota) | 1,496.19 mi (2,407.89 km) |
| Ontario to Menifee (California) | 34.12 mi (54.91 km) |
| Ontario to Menlo Park (California) | 348.54 mi (560.92 km) |
| Ontario to Menomonee Falls (Wisconsin) | 1,701.05 mi (2,737.58 km) |
| Ontario to Menomonie (Wisconsin) | 1,552.76 mi (2,498.93 km) |
| Ontario to Mentor (Ohio) | 2,031.48 mi (3,269.35 km) |
| Ontario to Mequon (Wisconsin) | 1,709.12 mi (2,750.56 km) |
| Ontario to Merced (California) | 277.29 mi (446.26 km) |
| Ontario to Mercedes (Texas) | 1,294.20 mi (2,082.81 km) |
| Ontario to Mercer Island (Washington) | 964.95 mi (1,552.94 km) |
| Ontario to Mercerville (New Jersey) | 2,378.61 mi (3,828.00 km) |
| Ontario to Meriden (Connecticut) | 2,472.51 mi (3,979.13 km) |
| Ontario to Meridian (Idaho) | 664.55 mi (1,069.49 km) |
| Ontario to Meridian (Mississippi) | 1,669.96 mi (2,687.54 km) |
