| Watford to Sestu | 967.70 mi (1,557.37 km) |
| Watford to Settimo Torinese | 585.16 mi (941.73 km) |
| Watford to Seveso | 600.67 mi (966.68 km) |
| Watford to Sezze | 946.28 mi (1,522.88 km) |
| Watford to Siano | 1,036.46 mi (1,668.03 km) |
| Watford to Siena | 792.85 mi (1,275.96 km) |
| Watford to Signa | 760.75 mi (1,224.31 km) |
| Watford to Silea | 710.78 mi (1,143.89 km) |
| Watford to Silvi Paese | 925.14 mi (1,488.87 km) |
| Watford to Sinalunga | 811.14 mi (1,305.41 km) |
| Watford to Siniscola | 903.54 mi (1,454.11 km) |
| Watford to Sinnai | 970.03 mi (1,561.11 km) |
| Watford to Siracusa | 1,265.45 mi (2,036.55 km) |
| Watford to Solaro | 600.36 mi (966.18 km) |
| Watford to Soliera | 705.80 mi (1,135.88 km) |
