| Potomac to Orthez | 3,838.73 mi (6,177.84 km) |
| Potomac to Orvault | 3,701.58 mi (5,957.12 km) |
| Potomac to Osny | 3,815.30 mi (6,140.13 km) |
| Potomac to Ostwald | 4,065.13 mi (6,542.20 km) |
| Potomac to Ouistreham | 3,711.94 mi (5,973.78 km) |
| Potomac to Oullins | 4,025.07 mi (6,477.72 km) |
| Potomac to Outreau | 3,755.14 mi (6,043.31 km) |
| Potomac to Oyonnax | 4,045.88 mi (6,511.22 km) |
| Potomac to Ozoir-la-Ferriere | 3,848.56 mi (6,193.67 km) |
| Potomac to Pace | 3,673.89 mi (5,912.56 km) |
| Potomac to Palaiseau | 3,831.88 mi (6,166.81 km) |
| Potomac to Pamiers | 3,958.41 mi (6,370.44 km) |
| Potomac to Panazol | 3,867.84 mi (6,224.69 km) |
| Potomac to Pantin | 3,833.76 mi (6,169.83 km) |
| Potomac to Paray-le-Monial | 3,973.76 mi (6,395.15 km) |
