| Merthyr Tudful to St. George (Utah) | 5,000.40 mi (8,047.37 km) |
| Merthyr Tudful to St. Helens (Oregon) | 4,796.32 mi (7,718.93 km) |
| Merthyr Tudful to St. James (New York) | 3,281.10 mi (5,280.43 km) |
| Merthyr Tudful to St. John (Indiana) | 3,829.38 mi (6,162.79 km) |
| Merthyr Tudful to St. Joseph (Missouri) | 4,190.11 mi (6,743.33 km) |
| Merthyr Tudful to St. Louis (Missouri) | 4,068.76 mi (6,548.04 km) |
| Merthyr Tudful to St. Louis Park (Minnesota) | 3,889.91 mi (6,260.21 km) |
| Merthyr Tudful to St. Marys (Georgia) | 4,097.74 mi (6,594.68 km) |
| Merthyr Tudful to St. Marys (Pennsylvania) | 3,475.42 mi (5,593.15 km) |
| Merthyr Tudful to St. Matthews (Kentucky) | 3,905.27 mi (6,284.93 km) |
| Merthyr Tudful to St. Michael (Minnesota) | 3,890.13 mi (6,260.56 km) |
| Merthyr Tudful to St. Paul (Minnesota) | 3,880.45 mi (6,244.98 km) |
| Merthyr Tudful to St. Peter (Minnesota) | 3,940.53 mi (6,341.67 km) |
| Merthyr Tudful to St. Peters (Missouri) | 4,075.80 mi (6,559.37 km) |
| Merthyr Tudful to St. Petersburg (Florida) | 4,290.55 mi (6,904.97 km) |
