| Pen-y-Bont ar Ogwr to Oerlinghausen | 524.28 mi (843.74 km) |
| Pen-y-Bont ar Ogwr to Oestrich-Winkel | 516.14 mi (830.64 km) |
| Pen-y-Bont ar Ogwr to Offenburg | 552.11 mi (888.53 km) |
| Pen-y-Bont ar Ogwr to Oftersheim | 554.49 mi (892.37 km) |
| Pen-y-Bont ar Ogwr to Ohrdruf | 620.80 mi (999.08 km) |
| Pen-y-Bont ar Ogwr to Ohringen | 597.27 mi (961.22 km) |
| Pen-y-Bont ar Ogwr to Olbernhau | 734.62 mi (1,182.25 km) |
| Pen-y-Bont ar Ogwr to Olching | 700.29 mi (1,127.01 km) |
| Pen-y-Bont ar Ogwr to Oldenburg | 510.01 mi (820.78 km) |
| Pen-y-Bont ar Ogwr to Oldenburg in Holstein | 631.49 mi (1,016.29 km) |
| Pen-y-Bont ar Ogwr to Olfen | 470.10 mi (756.56 km) |
| Pen-y-Bont ar Ogwr to Olpe | 494.05 mi (795.10 km) |
| Pen-y-Bont ar Ogwr to Olsberg | 519.13 mi (835.46 km) |
| Pen-y-Bont ar Ogwr to Oranienburg | 716.71 mi (1,153.44 km) |
| Pen-y-Bont ar Ogwr to Ortenberg | 555.15 mi (893.43 km) |
