| Potomac to Norwich | 3,698.51 mi (5,952.17 km) |
| Potomac to Nottingham | 3,594.48 mi (5,784.76 km) |
| Potomac to Nuneaton | 3,590.45 mi (5,778.28 km) |
| Potomac to Oadby | 3,604.63 mi (5,801.10 km) |
| Potomac to Oakengates | 3,547.54 mi (5,709.21 km) |
| Potomac to Oakham | 3,616.88 mi (5,820.81 km) |
| Potomac to Oldbury | 3,568.77 mi (5,743.38 km) |
| Potomac to Oldham | 3,544.61 mi (5,704.50 km) |
| Potomac to Ollerton | 3,594.70 mi (5,785.10 km) |
| Potomac to Olton | 3,578.58 mi (5,759.17 km) |
| Potomac to Omagh | 3,323.80 mi (5,349.14 km) |
| Potomac to Ormesby | 3,562.24 mi (5,732.87 km) |
| Potomac to Ormskirk | 3,513.76 mi (5,654.85 km) |
| Potomac to Orpington | 3,678.41 mi (5,919.83 km) |
| Potomac to Ossett | 3,563.19 mi (5,734.40 km) |
