| Holyhead to Sestu | 1,164.41 mi (1,873.94 km) |
| Holyhead to Settimo Torinese | 792.99 mi (1,276.20 km) |
| Holyhead to Seveso | 811.62 mi (1,306.18 km) |
| Holyhead to Sezze | 1,156.21 mi (1,860.73 km) |
| Holyhead to Siano | 1,247.19 mi (2,007.16 km) |
| Holyhead to Siena | 1,003.08 mi (1,614.29 km) |
| Holyhead to Signa | 971.31 mi (1,563.18 km) |
| Holyhead to Silea | 922.18 mi (1,484.10 km) |
| Holyhead to Silvi Paese | 1,136.66 mi (1,829.27 km) |
| Holyhead to Sinalunga | 1,021.66 mi (1,644.21 km) |
| Holyhead to Siniscola | 1,105.20 mi (1,778.65 km) |
| Holyhead to Sinnai | 1,167.14 mi (1,878.33 km) |
| Holyhead to Siracusa | 1,472.96 mi (2,370.51 km) |
| Holyhead to Solaro | 811.23 mi (1,305.54 km) |
| Holyhead to Soliera | 917.16 mi (1,476.03 km) |
