| Duzce to Oerlinghausen | 1,309.90 mi (2,108.08 km) |
| Duzce to Oestrich-Winkel | 1,281.40 mi (2,062.22 km) |
| Duzce to Offenburg | 1,250.68 mi (2,012.77 km) |
| Duzce to Oftersheim | 1,241.84 mi (1,998.54 km) |
| Duzce to Ohrdruf | 1,194.73 mi (1,922.73 km) |
| Duzce to Ohringen | 1,199.05 mi (1,929.68 km) |
| Duzce to Olbernhau | 1,090.26 mi (1,754.60 km) |
| Duzce to Olching | 1,097.30 mi (1,765.94 km) |
| Duzce to Oldenburg | 1,365.05 mi (2,196.83 km) |
| Duzce to Oldenburg in Holstein | 1,316.80 mi (2,119.19 km) |
| Duzce to Olfen | 1,351.78 mi (2,175.47 km) |
| Duzce to Olpe | 1,314.49 mi (2,115.46 km) |
| Duzce to Olsberg | 1,298.23 mi (2,089.31 km) |
| Duzce to Oranienburg | 1,175.37 mi (1,891.57 km) |
| Duzce to Ortenberg | 1,247.31 mi (2,007.35 km) |
