| Boulogne-sur-Mer to Settimo Torinese | 479.70 mi (772.00 km) |
| Boulogne-sur-Mer to Seveso | 492.92 mi (793.27 km) |
| Boulogne-sur-Mer to Sezze | 839.04 mi (1,350.30 km) |
| Boulogne-sur-Mer to Siano | 928.75 mi (1,494.68 km) |
| Boulogne-sur-Mer to Siena | 685.48 mi (1,103.18 km) |
| Boulogne-sur-Mer to Signa | 653.20 mi (1,051.22 km) |
| Boulogne-sur-Mer to Silea | 603.11 mi (970.62 km) |
| Boulogne-sur-Mer to Silvi Paese | 817.04 mi (1,314.91 km) |
| Boulogne-sur-Mer to Sinalunga | 703.59 mi (1,132.33 km) |
| Boulogne-sur-Mer to Siniscola | 801.62 mi (1,290.08 km) |
| Boulogne-sur-Mer to Sinnai | 870.90 mi (1,401.57 km) |
| Boulogne-sur-Mer to Siracusa | 1,159.50 mi (1,866.03 km) |
| Boulogne-sur-Mer to Solaro | 492.66 mi (792.86 km) |
| Boulogne-sur-Mer to Soliera | 597.79 mi (962.05 km) |
| Boulogne-sur-Mer to Solofra | 932.11 mi (1,500.09 km) |
