| Merthyr Tudful to Somersworth (New Hampshire) | 3,089.63 mi (4,972.28 km) |
| Merthyr Tudful to Somerton (Arizona) | 5,285.79 mi (8,506.66 km) |
| Merthyr Tudful to Somerville (Massachusetts) | 3,133.50 mi (5,042.87 km) |
| Merthyr Tudful to Somerville (New Jersey) | 3,354.13 mi (5,397.95 km) |
| Merthyr Tudful to Sonoma (California) | 5,216.66 mi (8,395.41 km) |
| Merthyr Tudful to Soquel (California) | 5,275.04 mi (8,489.36 km) |
| Merthyr Tudful to South Bend (Indiana) | 3,772.12 mi (6,070.64 km) |
| Merthyr Tudful to South Bradenton (Florida) | 4,303.70 mi (6,926.13 km) |
| Merthyr Tudful to South Burlington (Vermont) | 3,136.00 mi (5,046.91 km) |
| Merthyr Tudful to South Charleston (West Virginia) | 3,743.16 mi (6,024.04 km) |
| Merthyr Tudful to South Daytona (Florida) | 4,152.32 mi (6,682.52 km) |
| Merthyr Tudful to South El Monte (California) | 5,317.86 mi (8,558.27 km) |
| Merthyr Tudful to South Elgin (Illinois) | 3,836.82 mi (6,174.77 km) |
| Merthyr Tudful to South Euclid (Ohio) | 3,592.23 mi (5,781.13 km) |
| Merthyr Tudful to South Farmingdale (New York) | 3,300.02 mi (5,310.87 km) |
