| Merthyr Tudful to Crest Hill (Illinois) | 3,848.29 mi (6,193.22 km) |
| Merthyr Tudful to Crestview (Florida) | 4,306.20 mi (6,930.16 km) |
| Merthyr Tudful to Crestwood (Illinois) | 3,830.54 mi (6,164.66 km) |
| Merthyr Tudful to Crestwood (Missouri) | 4,077.73 mi (6,562.47 km) |
| Merthyr Tudful to Creve Coeur (Missouri) | 4,075.22 mi (6,558.43 km) |
| Merthyr Tudful to Crofton (Maryland) | 3,507.25 mi (5,644.37 km) |
| Merthyr Tudful to Crossville (Tennessee) | 3,989.25 mi (6,420.08 km) |
| Merthyr Tudful to Crowley (Louisiana) | 4,569.57 mi (7,354.01 km) |
| Merthyr Tudful to Crowley (Texas) | 4,647.03 mi (7,478.68 km) |
| Merthyr Tudful to Crown Point (Indiana) | 3,825.88 mi (6,157.17 km) |
| Merthyr Tudful to Crystal (Minnesota) | 3,885.63 mi (6,253.31 km) |
| Merthyr Tudful to Crystal Lake (Illinois) | 3,826.54 mi (6,158.22 km) |
| Merthyr Tudful to Cudahy (California) | 5,327.18 mi (8,573.26 km) |
| Merthyr Tudful to Cudahy (Wisconsin) | 3,776.05 mi (6,076.96 km) |
| Merthyr Tudful to Cullman (Alabama) | 4,148.17 mi (6,675.84 km) |
