| Seattle to Sestu | 5,730.93 mi (9,223.04 km) |
| Seattle to Settimo Torinese | 5,351.12 mi (8,611.79 km) |
| Seattle to Seveso | 5,355.85 mi (8,619.40 km) |
| Seattle to Sezze | 5,701.94 mi (9,176.38 km) |
| Seattle to Siano | 5,784.26 mi (9,308.87 km) |
| Seattle to Siena | 5,549.12 mi (8,930.45 km) |
| Seattle to Signa | 5,515.48 mi (8,876.30 km) |
| Seattle to Silea | 5,432.00 mi (8,741.95 km) |
| Seattle to Silvi Paese | 5,663.53 mi (9,114.57 km) |
| Seattle to Sinalunga | 5,565.20 mi (8,956.32 km) |
| Seattle to Siniscola | 5,671.27 mi (9,127.03 km) |
| Seattle to Sinnai | 5,733.76 mi (9,227.60 km) |
| Seattle to Siracusa | 6,028.11 mi (9,701.31 km) |
| Seattle to Solaro | 5,356.19 mi (8,619.95 km) |
| Seattle to Soliera | 5,453.97 mi (8,777.31 km) |
