| Duncan to Oerlinghausen | 5,005.12 mi (8,054.97 km) |
| Duncan to Oestrich-Winkel | 5,057.37 mi (8,139.05 km) |
| Duncan to Offenburg | 5,114.63 mi (8,231.20 km) |
| Duncan to Oftersheim | 5,103.51 mi (8,213.31 km) |
| Duncan to Ohrdruf | 5,123.18 mi (8,244.97 km) |
| Duncan to Ohringen | 5,144.06 mi (8,278.57 km) |
| Duncan to Olbernhau | 5,221.03 mi (8,402.43 km) |
| Duncan to Olching | 5,251.70 mi (8,451.79 km) |
| Duncan to Oldenburg | 4,944.08 mi (7,956.72 km) |
| Duncan to Oldenburg in Holstein | 4,989.34 mi (8,029.57 km) |
| Duncan to Olfen | 4,969.13 mi (7,997.04 km) |
| Duncan to Olpe | 5,012.03 mi (8,066.09 km) |
| Duncan to Olsberg | 5,022.52 mi (8,082.96 km) |
| Duncan to Oranienburg | 5,130.32 mi (8,256.45 km) |
| Duncan to Ortenberg | 5,081.95 mi (8,178.61 km) |
