| Sluis to Olympia Heights (Florida) | 4,587.87 mi (7,383.47 km) |
| Sluis to Omaha (Nebraska) | 4,424.93 mi (7,121.23 km) |
| Sluis to On Top of the World Designated Place (Florida) | 4,498.67 mi (7,239.91 km) |
| Sluis to Onalaska (Wisconsin) | 4,122.62 mi (6,634.72 km) |
| Sluis to Oneida (New York) | 3,571.87 mi (5,748.37 km) |
| Sluis to Oneonta (New York) | 3,575.11 mi (5,753.58 km) |
| Sluis to Ontario (California) | 5,541.46 mi (8,918.12 km) |
| Sluis to Ontario (Oregon) | 4,948.74 mi (7,964.23 km) |
| Sluis to Opa-locka (Florida) | 4,575.42 mi (7,363.43 km) |
| Sluis to Opelika (Alabama) | 4,447.42 mi (7,157.42 km) |
| Sluis to Opelousas (Louisiana) | 4,823.42 mi (7,762.55 km) |
| Sluis to Orange (California) | 5,561.83 mi (8,950.90 km) |
| Sluis to Orange (Texas) | 4,910.37 mi (7,902.47 km) |
| Sluis to Orange City (Florida) | 4,465.74 mi (7,186.91 km) |
| Sluis to Orangeburg (South Carolina) | 4,223.25 mi (6,796.66 km) |
