| Merthyr Tudful to Karditsa | 1,480.67 mi (2,382.91 km) |
| Merthyr Tudful to Kastoria | 1,401.46 mi (2,255.43 km) |
| Merthyr Tudful to Katerini | 1,461.42 mi (2,351.92 km) |
| Merthyr Tudful to Keratsini | 1,613.85 mi (2,597.25 km) |
| Merthyr Tudful to Kerkyra | 1,391.93 mi (2,240.10 km) |
| Merthyr Tudful to Kiato | 1,578.39 mi (2,540.18 km) |
| Merthyr Tudful to Kifisia | 1,615.93 mi (2,600.58 km) |
| Merthyr Tudful to Kilkis | 1,443.73 mi (2,323.46 km) |
| Merthyr Tudful to Komotini | 1,541.90 mi (2,481.44 km) |
| Merthyr Tudful to Korinthos | 1,588.72 mi (2,556.80 km) |
| Merthyr Tudful to Koropi | 1,627.02 mi (2,618.44 km) |
| Merthyr Tudful to Korydallos | 1,614.33 mi (2,598.02 km) |
| Merthyr Tudful to Kos | 1,809.35 mi (2,911.87 km) |
| Merthyr Tudful to Kozani | 1,431.69 mi (2,304.08 km) |
| Merthyr Tudful to Lagos | 1,527.33 mi (2,458.00 km) |
