| Horizon City to Oerlinghausen | 5,448.50 mi (8,768.52 km) |
| Horizon City to Oestrich-Winkel | 5,509.33 mi (8,866.40 km) |
| Horizon City to Offenburg | 5,572.18 mi (8,967.56 km) |
| Horizon City to Oftersheim | 5,556.75 mi (8,942.72 km) |
| Horizon City to Ohrdruf | 5,567.21 mi (8,959.56 km) |
| Horizon City to Ohringen | 5,596.30 mi (9,006.37 km) |
| Horizon City to Olbernhau | 5,660.72 mi (9,110.05 km) |
| Horizon City to Olching | 5,704.17 mi (9,179.97 km) |
| Horizon City to Oldenburg | 5,383.58 mi (8,664.04 km) |
| Horizon City to Oldenburg in Holstein | 5,419.38 mi (8,721.64 km) |
| Horizon City to Olfen | 5,415.68 mi (8,715.70 km) |
| Horizon City to Olpe | 5,460.50 mi (8,787.82 km) |
| Horizon City to Olsberg | 5,468.59 mi (8,800.85 km) |
| Horizon City to Oranienburg | 5,562.16 mi (8,951.43 km) |
| Horizon City to Ortenberg | 5,530.77 mi (8,900.91 km) |
