| San Sebastiano al Vesuvio to Olympia Heights (Florida) | 5,308.27 mi (8,542.84 km) |
| San Sebastiano al Vesuvio to Omaha (Nebraska) | 5,288.27 mi (8,510.65 km) |
| San Sebastiano al Vesuvio to On Top of the World Designated Place (Florida) | 5,252.97 mi (8,453.84 km) |
| San Sebastiano al Vesuvio to Onalaska (Wisconsin) | 4,983.57 mi (8,020.28 km) |
| San Sebastiano al Vesuvio to Oneida (New York) | 4,387.00 mi (7,060.19 km) |
| San Sebastiano al Vesuvio to Oneonta (New York) | 4,384.38 mi (7,055.98 km) |
| San Sebastiano al Vesuvio to Ontario (California) | 6,429.50 mi (10,347.29 km) |
| San Sebastiano al Vesuvio to Ontario (Oregon) | 5,841.51 mi (9,401.00 km) |
| San Sebastiano al Vesuvio to Opa-locka (Florida) | 5,296.56 mi (8,523.99 km) |
| San Sebastiano al Vesuvio to Opelika (Alabama) | 5,238.25 mi (8,430.15 km) |
| San Sebastiano al Vesuvio to Opelousas (Louisiana) | 5,632.09 mi (9,063.97 km) |
| San Sebastiano al Vesuvio to Orange (California) | 6,449.90 mi (10,380.12 km) |
| San Sebastiano al Vesuvio to Orange (Texas) | 5,724.15 mi (9,212.13 km) |
| San Sebastiano al Vesuvio to Orange City (Florida) | 5,213.60 mi (8,390.48 km) |
| San Sebastiano al Vesuvio to Orangeburg (South Carolina) | 4,998.65 mi (8,044.54 km) |
