| Seia to Oerlinghausen | 1,112.72 mi (1,790.76 km) |
| Seia to Oestrich-Winkel | 1,007.37 mi (1,621.21 km) |
| Seia to Offenburg | 947.74 mi (1,525.23 km) |
| Seia to Oftersheim | 1,005.22 mi (1,617.75 km) |
| Seia to Ohrdruf | 1,139.27 mi (1,833.48 km) |
| Seia to Ohringen | 1,034.74 mi (1,665.25 km) |
| Seia to Olbernhau | 1,232.83 mi (1,984.05 km) |
| Seia to Olching | 1,078.78 mi (1,736.13 km) |
| Seia to Oldenburg | 1,152.17 mi (1,854.24 km) |
| Seia to Oldenburg in Holstein | 1,286.72 mi (2,070.78 km) |
| Seia to Olfen | 1,059.81 mi (1,705.60 km) |
| Seia to Olpe | 1,043.59 mi (1,679.49 km) |
| Seia to Olsberg | 1,079.95 mi (1,738.01 km) |
| Seia to Oranienburg | 1,300.83 mi (2,093.49 km) |
| Seia to Ortenberg | 1,059.78 mi (1,705.55 km) |
