| Isernia to Oerlinghausen | 762.51 mi (1,227.14 km) |
| Isernia to Oestrich-Winkel | 652.87 mi (1,050.68 km) |
| Isernia to Offenburg | 565.00 mi (909.28 km) |
| Isernia to Oftersheim | 602.15 mi (969.06 km) |
| Isernia to Ohrdruf | 658.89 mi (1,060.38 km) |
| Isernia to Ohringen | 572.78 mi (921.80 km) |
| Isernia to Olbernhau | 627.74 mi (1,010.26 km) |
| Isernia to Olching | 477.65 mi (768.70 km) |
| Isernia to Oldenburg | 845.05 mi (1,359.97 km) |
| Isernia to Oldenburg in Holstein | 890.67 mi (1,433.40 km) |
| Isernia to Olfen | 769.92 mi (1,239.06 km) |
| Isernia to Olpe | 718.05 mi (1,155.60 km) |
| Isernia to Olsberg | 726.47 mi (1,169.14 km) |
| Isernia to Oranienburg | 771.92 mi (1,242.28 km) |
| Isernia to Ortenberg | 653.59 mi (1,051.86 km) |
