| Dartford to Olympia Heights (Florida) | 4,452.12 mi (7,165.00 km) |
| Dartford to Omaha (Nebraska) | 4,305.98 mi (6,929.81 km) |
| Dartford to On Top of the World Designated Place (Florida) | 4,364.44 mi (7,023.88 km) |
| Dartford to Onalaska (Wisconsin) | 4,002.82 mi (6,441.91 km) |
| Dartford to Oneida (New York) | 3,442.62 mi (5,540.35 km) |
| Dartford to Oneonta (New York) | 3,445.10 mi (5,544.35 km) |
| Dartford to Ontario (California) | 5,435.02 mi (8,746.82 km) |
| Dartford to Ontario (Oregon) | 4,850.90 mi (7,806.78 km) |
| Dartford to Opa-locka (Florida) | 4,439.69 mi (7,145.00 km) |
| Dartford to Opelika (Alabama) | 4,315.93 mi (6,945.82 km) |
| Dartford to Opelousas (Louisiana) | 4,694.08 mi (7,554.39 km) |
| Dartford to Orange (California) | 5,455.42 mi (8,779.64 km) |
| Dartford to Orange (Texas) | 4,781.72 mi (7,695.43 km) |
| Dartford to Orange City (Florida) | 4,331.13 mi (6,970.28 km) |
| Dartford to Orangeburg (South Carolina) | 4,090.30 mi (6,582.71 km) |
