| Merthyr Tudful to Clarkston (Georgia) | 4,059.75 mi (6,533.54 km) |
| Merthyr Tudful to Clarksville (Indiana) | 3,907.03 mi (6,287.76 km) |
| Merthyr Tudful to Clarksville (Tennessee) | 4,052.90 mi (6,522.51 km) |
| Merthyr Tudful to Clawson (Michigan) | 3,611.80 mi (5,812.63 km) |
| Merthyr Tudful to Clay (Alabama) | 4,162.25 mi (6,698.50 km) |
| Merthyr Tudful to Clayton (California) | 5,220.55 mi (8,401.66 km) |
| Merthyr Tudful to Clayton (Missouri) | 4,071.67 mi (6,552.73 km) |
| Merthyr Tudful to Clayton (North Carolina) | 3,733.09 mi (6,007.83 km) |
| Merthyr Tudful to Clayton (Ohio) | 3,778.19 mi (6,080.40 km) |
| Merthyr Tudful to Clearfield (Utah) | 4,730.53 mi (7,613.05 km) |
| Merthyr Tudful to Clearlake (California) | 5,183.58 mi (8,342.17 km) |
| Merthyr Tudful to Clearwater (Florida) | 4,285.32 mi (6,896.55 km) |
| Merthyr Tudful to Cleburne (Texas) | 4,660.60 mi (7,500.51 km) |
| Merthyr Tudful to Clemmons (North Carolina) | 3,795.77 mi (6,108.70 km) |
| Merthyr Tudful to Clemson (South Carolina) | 3,959.24 mi (6,371.78 km) |
