| Caerphilly to Oberkirch | 542.96 mi (873.80 km) |
| Caerphilly to Obernburg am Main | 553.22 mi (890.32 km) |
| Caerphilly to Obernkirchen | 527.15 mi (848.37 km) |
| Caerphilly to Oberschleissheim | 695.36 mi (1,119.07 km) |
| Caerphilly to Oberstdorf | 669.36 mi (1,077.23 km) |
| Caerphilly to Obertraubling | 701.50 mi (1,128.95 km) |
| Caerphilly to Obertshausen | 535.63 mi (862.01 km) |
| Caerphilly to Oberursel | 522.17 mi (840.35 km) |
| Caerphilly to Ochsenfurt | 596.57 mi (960.08 km) |
| Caerphilly to Ochsenhausen | 633.75 mi (1,019.92 km) |
| Caerphilly to Ochtrup | 445.54 mi (717.03 km) |
| Caerphilly to Odenthal | 447.61 mi (720.36 km) |
| Caerphilly to Oelde | 486.57 mi (783.06 km) |
| Caerphilly to Oelsnitz | 672.52 mi (1,082.31 km) |
| Caerphilly to Oer-Erkenschwick | 448.83 mi (722.32 km) |
