| Rocky River to Oerlinghausen | 4,065.48 mi (6,542.75 km) |
| Rocky River to Oestrich-Winkel | 4,106.46 mi (6,608.71 km) |
| Rocky River to Offenburg | 4,156.64 mi (6,689.46 km) |
| Rocky River to Oftersheim | 4,150.77 mi (6,680.02 km) |
| Rocky River to Ohrdruf | 4,181.85 mi (6,730.04 km) |
| Rocky River to Ohringen | 4,192.30 mi (6,746.86 km) |
| Rocky River to Olbernhau | 4,284.60 mi (6,895.40 km) |
| Rocky River to Olching | 4,299.04 mi (6,918.63 km) |
| Rocky River to Oldenburg | 4,010.03 mi (6,453.51 km) |
| Rocky River to Oldenburg in Holstein | 4,067.82 mi (6,546.53 km) |
| Rocky River to Olfen | 4,025.62 mi (6,478.60 km) |
| Rocky River to Olpe | 4,065.79 mi (6,543.26 km) |
| Rocky River to Olsberg | 4,079.25 mi (6,564.92 km) |
| Rocky River to Oranienburg | 4,205.05 mi (6,767.38 km) |
| Rocky River to Ortenberg | 4,134.81 mi (6,654.34 km) |
