| Clausthal-Zellerfeld to Oestrich-Winkel | 160.95 mi (259.02 km) |
| Clausthal-Zellerfeld to Offenburg | 253.97 mi (408.73 km) |
| Clausthal-Zellerfeld to Oftersheim | 184.89 mi (297.56 km) |
| Clausthal-Zellerfeld to Ohrdruf | 69.64 mi (112.08 km) |
| Clausthal-Zellerfeld to Ohringen | 183.69 mi (295.62 km) |
| Clausthal-Zellerfeld to Olbernhau | 151.65 mi (244.06 km) |
| Clausthal-Zellerfeld to Olching | 252.86 mi (406.93 km) |
| Clausthal-Zellerfeld to Oldenburg | 128.56 mi (206.90 km) |
| Clausthal-Zellerfeld to Oldenburg in Holstein | 173.88 mi (279.83 km) |
| Clausthal-Zellerfeld to Olfen | 126.39 mi (203.41 km) |
| Clausthal-Zellerfeld to Olpe | 120.80 mi (194.41 km) |
| Clausthal-Zellerfeld to Olsberg | 85.52 mi (137.63 km) |
| Clausthal-Zellerfeld to Oranienburg | 139.07 mi (223.81 km) |
| Clausthal-Zellerfeld to Ortenberg | 114.51 mi (184.29 km) |
| Clausthal-Zellerfeld to Oschatz | 124.07 mi (199.66 km) |
