| Merthyr Tudful to Storm Lake (Iowa) | 4,065.14 mi (6,542.22 km) |
| Merthyr Tudful to Storrs (Connecticut) | 3,204.82 mi (5,157.65 km) |
| Merthyr Tudful to Stoughton (Wisconsin) | 3,828.83 mi (6,161.90 km) |
| Merthyr Tudful to Stow (Ohio) | 3,604.01 mi (5,800.10 km) |
| Merthyr Tudful to Streamwood (Illinois) | 3,830.22 mi (6,164.15 km) |
| Merthyr Tudful to Streator (Illinois) | 3,896.64 mi (6,271.04 km) |
| Merthyr Tudful to Streetsboro (Ohio) | 3,597.68 mi (5,789.90 km) |
| Merthyr Tudful to Strongsville (Ohio) | 3,613.78 mi (5,815.82 km) |
| Merthyr Tudful to Stuart (Florida) | 4,218.25 mi (6,788.62 km) |
| Merthyr Tudful to Stuarts Draft (Virginia) | 3,648.70 mi (5,872.01 km) |
| Merthyr Tudful to Sturgis (Michigan) | 3,733.42 mi (6,008.35 km) |
| Merthyr Tudful to Suamico (Wisconsin) | 3,708.02 mi (5,967.49 km) |
| Merthyr Tudful to Sudley (Virginia) | 3,550.88 mi (5,714.58 km) |
| Merthyr Tudful to Suffern (New York) | 3,311.67 mi (5,329.62 km) |
| Merthyr Tudful to Suffolk (Virginia) | 3,610.14 mi (5,809.96 km) |
