| Grevenmacher to Olympia Heights (Florida) | 4,744.94 mi (7,636.24 km) |
| Grevenmacher to Omaha (Nebraska) | 4,599.59 mi (7,402.32 km) |
| Grevenmacher to On Top of the World Designated Place (Florida) | 4,660.64 mi (7,500.57 km) |
| Grevenmacher to Onalaska (Wisconsin) | 4,297.09 mi (6,915.50 km) |
| Grevenmacher to Oneida (New York) | 3,741.40 mi (6,021.20 km) |
| Grevenmacher to Oneonta (New York) | 3,743.88 mi (6,025.19 km) |
| Grevenmacher to Ontario (California) | 5,715.91 mi (9,198.87 km) |
| Grevenmacher to Ontario (Oregon) | 5,121.04 mi (8,241.51 km) |
| Grevenmacher to Opa-locka (Florida) | 4,732.58 mi (7,616.36 km) |
| Grevenmacher to Opelika (Alabama) | 4,614.39 mi (7,426.14 km) |
| Grevenmacher to Opelousas (Louisiana) | 4,992.87 mi (8,035.25 km) |
| Grevenmacher to Orange (California) | 5,736.28 mi (9,231.64 km) |
| Grevenmacher to Orange (Texas) | 5,080.46 mi (8,176.22 km) |
| Grevenmacher to Orange City (Florida) | 4,626.74 mi (7,446.02 km) |
| Grevenmacher to Orangeburg (South Carolina) | 4,387.94 mi (7,061.71 km) |
