| Merthyr Tudful to Seysses | 609.79 mi (981.36 km) |
| Merthyr Tudful to Sin-le-Noble | 297.48 mi (478.76 km) |
| Merthyr Tudful to Six-Fours-les-Plages | 734.59 mi (1,182.20 km) |
| Merthyr Tudful to Soissons | 336.17 mi (541.01 km) |
| Merthyr Tudful to Soisy-sous-Montmorency | 314.27 mi (505.76 km) |
| Merthyr Tudful to Sollies-Pont | 735.46 mi (1,183.61 km) |
| Merthyr Tudful to Somain | 304.50 mi (490.05 km) |
| Merthyr Tudful to Sorgues | 656.22 mi (1,056.08 km) |
| Merthyr Tudful to Sotteville-les-Rouen | 253.76 mi (408.39 km) |
| Merthyr Tudful to Soyaux | 451.96 mi (727.35 km) |
| Merthyr Tudful to Stains | 318.85 mi (513.15 km) |
| Merthyr Tudful to Stiring-Wendel | 485.60 mi (781.50 km) |
| Merthyr Tudful to Strasbourg | 537.87 mi (865.61 km) |
| Merthyr Tudful to Sucy-en-Brie | 331.71 mi (533.84 km) |
| Merthyr Tudful to Suresnes | 316.75 mi (509.76 km) |
