| Fort Thomas to Oerlinghausen | 4,279.07 mi (6,886.50 km) |
| Fort Thomas to Oestrich-Winkel | 4,319.11 mi (6,950.94 km) |
| Fort Thomas to Offenburg | 4,368.44 mi (7,030.33 km) |
| Fort Thomas to Oftersheim | 4,363.21 mi (7,021.91 km) |
| Fort Thomas to Ohrdruf | 4,395.30 mi (7,073.55 km) |
| Fort Thomas to Ohringen | 4,404.84 mi (7,088.90 km) |
| Fort Thomas to Olbernhau | 4,498.33 mi (7,239.37 km) |
| Fort Thomas to Olching | 4,511.44 mi (7,260.46 km) |
| Fort Thomas to Oldenburg | 4,223.96 mi (6,797.80 km) |
| Fort Thomas to Oldenburg in Holstein | 4,282.20 mi (6,891.54 km) |
| Fort Thomas to Olfen | 4,238.95 mi (6,821.93 km) |
| Fort Thomas to Olpe | 4,278.89 mi (6,886.21 km) |
| Fort Thomas to Olsberg | 4,292.59 mi (6,908.26 km) |
| Fort Thomas to Oranienburg | 4,419.31 mi (7,112.19 km) |
| Fort Thomas to Ortenberg | 4,347.82 mi (6,997.13 km) |
