| Preakness to Oerlinghausen | 3,799.51 mi (6,114.71 km) |
| Preakness to Oestrich-Winkel | 3,828.73 mi (6,161.75 km) |
| Preakness to Offenburg | 3,870.90 mi (6,229.61 km) |
| Preakness to Oftersheim | 3,870.79 mi (6,229.43 km) |
| Preakness to Ohrdruf | 3,913.32 mi (6,297.87 km) |
| Preakness to Ohringen | 3,913.08 mi (6,297.49 km) |
| Preakness to Olbernhau | 4,020.01 mi (6,469.58 km) |
| Preakness to Olching | 4,018.16 mi (6,466.60 km) |
| Preakness to Oldenburg | 3,749.93 mi (6,034.93 km) |
| Preakness to Oldenburg in Holstein | 3,818.79 mi (6,145.75 km) |
| Preakness to Olfen | 3,756.12 mi (6,044.89 km) |
| Preakness to Olpe | 3,793.21 mi (6,104.58 km) |
| Preakness to Olsberg | 3,809.59 mi (6,130.94 km) |
| Preakness to Oranienburg | 3,951.42 mi (6,359.20 km) |
| Preakness to Ortenberg | 3,860.80 mi (6,213.36 km) |
