| Merthyr Tudful to Dover (New Jersey) | 3,338.52 mi (5,372.83 km) |
| Merthyr Tudful to Dover (Ohio) | 3,634.62 mi (5,849.35 km) |
| Merthyr Tudful to Downers Grove (Illinois) | 3,834.39 mi (6,170.86 km) |
| Merthyr Tudful to Downey (California) | 5,326.88 mi (8,572.79 km) |
| Merthyr Tudful to Dranesville (Virginia) | 3,536.40 mi (5,691.28 km) |
| Merthyr Tudful to Draper (Utah) | 4,757.73 mi (7,656.82 km) |
| Merthyr Tudful to Drexel Heights (Arizona) | 5,182.62 mi (8,340.61 km) |
| Merthyr Tudful to Drexel Hill (Pennsylvania) | 3,409.52 mi (5,487.10 km) |
| Merthyr Tudful to Duarte (California) | 5,308.32 mi (8,542.92 km) |
| Merthyr Tudful to Dublin (California) | 5,232.34 mi (8,420.63 km) |
| Merthyr Tudful to Dublin (Georgia) | 4,067.41 mi (6,545.86 km) |
| Merthyr Tudful to Dublin (Ohio) | 3,720.02 mi (5,986.80 km) |
| Merthyr Tudful to Dubuque (Iowa) | 3,904.53 mi (6,283.73 km) |
| Merthyr Tudful to Duluth (Georgia) | 4,046.67 mi (6,512.49 km) |
| Merthyr Tudful to Duluth (Minnesota) | 3,762.42 mi (6,055.02 km) |
