| Llantrisant to Oerlinghausen | 515.28 mi (829.26 km) |
| Llantrisant to Oestrich-Winkel | 507.77 mi (817.18 km) |
| Llantrisant to Offenburg | 544.55 mi (876.37 km) |
| Llantrisant to Oftersheim | 546.36 mi (879.29 km) |
| Llantrisant to Ohrdruf | 612.01 mi (984.94 km) |
| Llantrisant to Ohringen | 589.12 mi (948.10 km) |
| Llantrisant to Olbernhau | 725.80 mi (1,168.06 km) |
| Llantrisant to Olching | 692.35 mi (1,114.23 km) |
| Llantrisant to Oldenburg | 500.94 mi (806.19 km) |
| Llantrisant to Oldenburg in Holstein | 622.51 mi (1,001.84 km) |
| Llantrisant to Olfen | 461.16 mi (742.16 km) |
| Llantrisant to Olpe | 485.30 mi (781.01 km) |
| Llantrisant to Olsberg | 510.26 mi (821.19 km) |
| Llantrisant to Oranienburg | 707.65 mi (1,138.86 km) |
| Llantrisant to Ortenberg | 546.57 mi (879.62 km) |
