| Kastamonu to Oerlinghausen | 1,386.69 mi (2,231.66 km) |
| Kastamonu to Oestrich-Winkel | 1,370.14 mi (2,205.03 km) |
| Kastamonu to Offenburg | 1,347.88 mi (2,169.21 km) |
| Kastamonu to Oftersheim | 1,333.41 mi (2,145.91 km) |
| Kastamonu to Ohrdruf | 1,274.72 mi (2,051.46 km) |
| Kastamonu to Ohringen | 1,290.51 mi (2,076.87 km) |
| Kastamonu to Olbernhau | 1,166.11 mi (1,876.67 km) |
| Kastamonu to Olching | 1,192.40 mi (1,918.99 km) |
| Kastamonu to Oldenburg | 1,436.01 mi (2,311.04 km) |
| Kastamonu to Oldenburg in Holstein | 1,376.23 mi (2,214.83 km) |
| Kastamonu to Olfen | 1,431.84 mi (2,304.32 km) |
| Kastamonu to Olpe | 1,397.80 mi (2,249.54 km) |
| Kastamonu to Olsberg | 1,378.78 mi (2,218.93 km) |
| Kastamonu to Oranienburg | 1,238.29 mi (1,992.83 km) |
| Kastamonu to Ortenberg | 1,332.69 mi (2,144.76 km) |
