| Seattle to Opwijk | 4,923.60 mi (7,923.77 km) |
| Seattle to Ostend | 4,877.30 mi (7,849.26 km) |
| Seattle to Oud-Heverlee | 4,943.18 mi (7,955.28 km) |
| Seattle to Oud-Turnhout | 4,923.46 mi (7,923.54 km) |
| Seattle to Oudenaarde | 4,915.60 mi (7,910.90 km) |
| Seattle to Oudenburg | 4,881.72 mi (7,856.37 km) |
| Seattle to Oupeye | 4,974.34 mi (8,005.43 km) |
| Seattle to Overijse | 4,942.71 mi (7,954.53 km) |
| Seattle to Overpelt | 4,939.73 mi (7,949.73 km) |
| Seattle to Paal | 4,943.91 mi (7,956.46 km) |
| Seattle to Peer | 4,945.42 mi (7,958.89 km) |
| Seattle to Pepinster | 4,986.71 mi (8,025.33 km) |
| Seattle to Peruwelz | 4,934.00 mi (7,940.51 km) |
| Seattle to Perwez | 4,958.77 mi (7,980.36 km) |
| Seattle to Philippeville | 4,976.31 mi (8,008.60 km) |
