| Niagara Falls to Sestu | 4,364.49 mi (7,023.97 km) |
| Niagara Falls to Settimo Torinese | 4,085.34 mi (6,574.72 km) |
| Niagara Falls to Seveso | 4,123.01 mi (6,635.34 km) |
| Niagara Falls to Sezze | 4,446.38 mi (7,155.76 km) |
| Niagara Falls to Siano | 4,543.13 mi (7,311.46 km) |
| Niagara Falls to Siena | 4,301.65 mi (6,922.84 km) |
| Niagara Falls to Signa | 4,273.99 mi (6,878.32 km) |
| Niagara Falls to Silea | 4,250.48 mi (6,840.49 km) |
| Niagara Falls to Silvi Paese | 4,447.36 mi (7,157.34 km) |
| Niagara Falls to Sinalunga | 4,322.29 mi (6,956.05 km) |
| Niagara Falls to Siniscola | 4,340.22 mi (6,984.91 km) |
| Niagara Falls to Sinnai | 4,369.23 mi (7,031.59 km) |
| Niagara Falls to Siracusa | 4,726.12 mi (7,605.96 km) |
| Niagara Falls to Solaro | 4,121.87 mi (6,633.51 km) |
| Niagara Falls to Soliera | 4,230.05 mi (6,807.60 km) |
