| Potomac to Solofra | 4,629.64 mi (7,450.68 km) |
| Potomac to Somma Lombardo | 4,194.46 mi (6,750.33 km) |
| Potomac to Somma Vesuviana | 4,609.95 mi (7,419.00 km) |
| Potomac to Sommacampagna | 4,295.54 mi (6,913.01 km) |
| Potomac to Sona | 4,293.73 mi (6,910.09 km) |
| Potomac to Sondrio | 4,228.82 mi (6,805.64 km) |
| Potomac to Sora | 4,542.97 mi (7,311.21 km) |
| Potomac to Sorbolo | 4,296.68 mi (6,914.84 km) |
| Potomac to Soresina | 4,256.83 mi (6,850.70 km) |
| Potomac to Sorisole | 4,233.64 mi (6,813.39 km) |
| Potomac to Sorrento | 4,616.19 mi (7,429.04 km) |
| Potomac to Sorso | 4,349.76 mi (7,000.27 km) |
| Potomac to Sortino | 4,776.44 mi (7,686.94 km) |
| Potomac to Soverato Marina | 4,786.60 mi (7,703.28 km) |
| Potomac to Sovicille | 4,383.35 mi (7,054.33 km) |
