| Pikesville to Oerlinghausen | 3,968.26 mi (6,386.29 km) |
| Pikesville to Oestrich-Winkel | 3,997.73 mi (6,433.72 km) |
| Pikesville to Offenburg | 4,039.89 mi (6,501.58 km) |
| Pikesville to Oftersheim | 4,039.80 mi (6,501.43 km) |
| Pikesville to Ohrdruf | 4,082.15 mi (6,569.59 km) |
| Pikesville to Ohringen | 4,082.09 mi (6,569.48 km) |
| Pikesville to Olbernhau | 4,188.74 mi (6,741.12 km) |
| Pikesville to Olching | 4,187.17 mi (6,738.60 km) |
| Pikesville to Oldenburg | 3,918.45 mi (6,306.14 km) |
| Pikesville to Oldenburg in Holstein | 3,986.75 mi (6,416.05 km) |
| Pikesville to Olfen | 3,924.97 mi (6,316.63 km) |
| Pikesville to Olpe | 3,962.13 mi (6,376.44 km) |
| Pikesville to Olsberg | 3,978.44 mi (6,402.69 km) |
| Pikesville to Oranienburg | 4,119.68 mi (6,629.98 km) |
| Pikesville to Ortenberg | 4,029.75 mi (6,485.26 km) |
