| Ballincollig to Oerlinghausen | 733.52 mi (1,180.49 km) |
| Ballincollig to Oestrich-Winkel | 732.21 mi (1,178.38 km) |
| Ballincollig to Offenburg | 766.39 mi (1,233.38 km) |
| Ballincollig to Oftersheim | 770.57 mi (1,240.12 km) |
| Ballincollig to Ohrdruf | 834.39 mi (1,342.83 km) |
| Ballincollig to Ohringen | 813.38 mi (1,309.01 km) |
| Ballincollig to Olbernhau | 947.65 mi (1,525.10 km) |
| Ballincollig to Olching | 915.99 mi (1,474.15 km) |
| Ballincollig to Oldenburg | 710.15 mi (1,142.87 km) |
| Ballincollig to Oldenburg in Holstein | 822.13 mi (1,323.10 km) |
| Ballincollig to Olfen | 681.17 mi (1,096.24 km) |
| Ballincollig to Olpe | 708.14 mi (1,139.64 km) |
| Ballincollig to Olsberg | 731.66 mi (1,177.49 km) |
| Ballincollig to Oranienburg | 920.16 mi (1,480.85 km) |
| Ballincollig to Ortenberg | 770.54 mi (1,240.07 km) |
