| Mendrisio to Olympia Heights (Florida) | 4,933.34 mi (7,939.45 km) |
| Mendrisio to Omaha (Nebraska) | 4,855.33 mi (7,813.90 km) |
| Mendrisio to On Top of the World Designated Place (Florida) | 4,863.40 mi (7,826.89 km) |
| Mendrisio to Onalaska (Wisconsin) | 4,551.32 mi (7,324.64 km) |
| Mendrisio to Oneida (New York) | 3,971.21 mi (6,391.04 km) |
| Mendrisio to Oneonta (New York) | 3,970.85 mi (6,390.47 km) |
| Mendrisio to Ontario (California) | 5,989.44 mi (9,639.06 km) |
| Mendrisio to Ontario (Oregon) | 5,401.86 mi (8,693.46 km) |
| Mendrisio to Opa-locka (Florida) | 4,921.29 mi (7,920.05 km) |
| Mendrisio to Opelika (Alabama) | 4,833.39 mi (7,778.60 km) |
| Mendrisio to Opelousas (Louisiana) | 5,220.45 mi (8,401.50 km) |
| Mendrisio to Orange (California) | 6,009.83 mi (9,671.89 km) |
| Mendrisio to Orange (Texas) | 5,310.53 mi (8,546.47 km) |
| Mendrisio to Orange City (Florida) | 4,826.68 mi (7,767.79 km) |
| Mendrisio to Orangeburg (South Carolina) | 4,599.76 mi (7,402.59 km) |
