| Portsmouth to Sestu | 935.55 mi (1,505.62 km) |
| Portsmouth to Settimo Torinese | 566.16 mi (911.15 km) |
| Portsmouth to Seveso | 589.66 mi (948.96 km) |
| Portsmouth to Sezze | 931.04 mi (1,498.37 km) |
| Portsmouth to Siano | 1,023.47 mi (1,647.12 km) |
| Portsmouth to Siena | 778.71 mi (1,253.21 km) |
| Portsmouth to Signa | 747.71 mi (1,203.33 km) |
| Portsmouth to Silea | 709.90 mi (1,142.47 km) |
| Portsmouth to Silvi Paese | 916.13 mi (1,474.37 km) |
| Portsmouth to Sinalunga | 797.85 mi (1,284.02 km) |
| Portsmouth to Siniscola | 875.91 mi (1,409.65 km) |
| Portsmouth to Sinnai | 938.20 mi (1,509.89 km) |
| Portsmouth to Siracusa | 1,245.11 mi (2,003.81 km) |
| Portsmouth to Solaro | 588.99 mi (947.89 km) |
| Portsmouth to Soliera | 696.35 mi (1,120.67 km) |
