| Portsmouth to Oerlinghausen | 427.81 mi (688.50 km) |
| Portsmouth to Oestrich-Winkel | 403.78 mi (649.82 km) |
| Portsmouth to Offenburg | 434.44 mi (699.16 km) |
| Portsmouth to Oftersheim | 439.73 mi (707.68 km) |
| Portsmouth to Ohrdruf | 515.43 mi (829.51 km) |
| Portsmouth to Ohringen | 482.63 mi (776.71 km) |
| Portsmouth to Olbernhau | 629.66 mi (1,013.34 km) |
| Portsmouth to Olching | 584.13 mi (940.06 km) |
| Portsmouth to Oldenburg | 427.17 mi (687.46 km) |
| Portsmouth to Oldenburg in Holstein | 556.89 mi (896.23 km) |
| Portsmouth to Olfen | 371.38 mi (597.68 km) |
| Portsmouth to Olpe | 388.66 mi (625.48 km) |
| Portsmouth to Olsberg | 416.84 mi (670.84 km) |
| Portsmouth to Oranienburg | 625.80 mi (1,007.13 km) |
| Portsmouth to Ortenberg | 445.72 mi (717.32 km) |
