| Mortsel to Olympia Heights (Florida) | 4,635.63 mi (7,460.32 km) |
| Mortsel to Omaha (Nebraska) | 4,468.90 mi (7,191.99 km) |
| Mortsel to On Top of the World Designated Place (Florida) | 4,546.26 mi (7,316.51 km) |
| Mortsel to Onalaska (Wisconsin) | 4,166.84 mi (6,705.88 km) |
| Mortsel to Oneida (New York) | 3,618.50 mi (5,823.41 km) |
| Mortsel to Oneonta (New York) | 3,621.90 mi (5,828.88 km) |
| Mortsel to Ontario (California) | 5,581.76 mi (8,982.98 km) |
| Mortsel to Ontario (Oregon) | 4,986.52 mi (8,025.03 km) |
| Mortsel to Opa-locka (Florida) | 4,623.17 mi (7,440.28 km) |
| Mortsel to Opelika (Alabama) | 4,494.51 mi (7,233.21 km) |
| Mortsel to Opelousas (Louisiana) | 4,870.04 mi (7,837.56 km) |
| Mortsel to Orange (California) | 5,602.12 mi (9,015.74 km) |
| Mortsel to Orange (Texas) | 4,956.82 mi (7,977.23 km) |
| Mortsel to Orange City (Florida) | 4,513.38 mi (7,263.59 km) |
| Mortsel to Orangeburg (South Carolina) | 4,270.63 mi (6,872.91 km) |
