| Heerlen to Oberkirch | 187.51 mi (301.77 km) |
| Heerlen to Obernburg am Main | 156.74 mi (252.25 km) |
| Heerlen to Obernkirchen | 165.05 mi (265.62 km) |
| Heerlen to Oberschleissheim | 309.22 mi (497.64 km) |
| Heerlen to Oberstdorf | 308.59 mi (496.63 km) |
| Heerlen to Obertraubling | 305.17 mi (491.13 km) |
| Heerlen to Obertshausen | 137.42 mi (221.16 km) |
| Heerlen to Oberursel | 123.18 mi (198.24 km) |
| Heerlen to Ochsenfurt | 199.43 mi (320.95 km) |
| Heerlen to Ochsenhausen | 263.37 mi (423.86 km) |
| Heerlen to Ochtrup | 105.05 mi (169.07 km) |
| Heerlen to Odenthal | 50.40 mi (81.12 km) |
| Heerlen to Oelde | 114.22 mi (183.82 km) |
| Heerlen to Oelsnitz | 272.72 mi (438.90 km) |
| Heerlen to Oer-Erkenschwick | 75.84 mi (122.06 km) |
