| Horsell to Olympia Heights (Florida) | 4,420.18 mi (7,113.59 km) |
| Horsell to Omaha (Nebraska) | 4,281.58 mi (6,890.54 km) |
| Horsell to On Top of the World Designated Place (Florida) | 4,333.49 mi (6,974.08 km) |
| Horsell to Onalaska (Wisconsin) | 3,978.13 mi (6,402.18 km) |
| Horsell to Oneida (New York) | 3,414.19 mi (5,494.60 km) |
| Horsell to Oneonta (New York) | 3,416.33 mi (5,498.05 km) |
| Horsell to Ontario (California) | 5,414.81 mi (8,714.29 km) |
| Horsell to Ontario (Oregon) | 4,833.52 mi (7,778.80 km) |
| Horsell to Opa-locka (Florida) | 4,407.77 mi (7,093.62 km) |
| Horsell to Opelika (Alabama) | 4,286.43 mi (6,898.34 km) |
| Horsell to Opelousas (Louisiana) | 4,665.54 mi (7,508.47 km) |
| Horsell to Orange (California) | 5,435.21 mi (8,747.13 km) |
| Horsell to Orange (Texas) | 4,753.48 mi (7,649.99 km) |
| Horsell to Orange City (Florida) | 4,299.96 mi (6,920.12 km) |
| Horsell to Orangeburg (South Carolina) | 4,060.08 mi (6,534.07 km) |
