| Merthyr Tudful to Sabadell | 750.37 mi (1,207.60 km) |
| Merthyr Tudful to Sabinanigo | 652.75 mi (1,050.49 km) |
| Merthyr Tudful to Sagunto | 846.87 mi (1,362.90 km) |
| Merthyr Tudful to Salamanca | 752.53 mi (1,211.07 km) |
| Merthyr Tudful to Salobrena | 1,036.19 mi (1,667.59 km) |
| Merthyr Tudful to Salou | 767.07 mi (1,234.48 km) |
| Merthyr Tudful to Salt | 734.37 mi (1,181.86 km) |
| Merthyr Tudful to Salvatierra de Mino | 709.41 mi (1,141.68 km) |
| Merthyr Tudful to Sama | 593.11 mi (954.51 km) |
| Merthyr Tudful to San Adrian de Besos | 759.90 mi (1,222.94 km) |
| Merthyr Tudful to San Agustin de Guadalix | 764.59 mi (1,230.49 km) |
| Merthyr Tudful to San Andres de la Barca | 754.88 mi (1,214.86 km) |
| Merthyr Tudful to San Andres de Llevaneras | 755.02 mi (1,215.08 km) |
| Merthyr Tudful to San Andres del Rabanedo | 639.06 mi (1,028.47 km) |
| Merthyr Tudful to San Bartolome | 1,762.75 mi (2,836.87 km) |
