| Gloucester to Oerlinghausen | 464.63 mi (747.75 km) |
| Gloucester to Oestrich-Winkel | 463.87 mi (746.53 km) |
| Gloucester to Offenburg | 507.34 mi (816.48 km) |
| Gloucester to Oftersheim | 504.45 mi (811.84 km) |
| Gloucester to Ohrdruf | 563.84 mi (907.41 km) |
| Gloucester to Ohringen | 546.92 mi (880.19 km) |
| Gloucester to Olbernhau | 677.20 mi (1,089.85 km) |
| Gloucester to Olching | 651.70 mi (1,048.81 km) |
| Gloucester to Oldenburg | 448.21 mi (721.33 km) |
| Gloucester to Oldenburg in Holstein | 569.25 mi (916.12 km) |
| Gloucester to Olfen | 411.28 mi (661.90 km) |
| Gloucester to Olpe | 437.60 mi (704.24 km) |
| Gloucester to Olsberg | 461.28 mi (742.36 km) |
| Gloucester to Oranienburg | 655.59 mi (1,055.06 km) |
| Gloucester to Ortenberg | 500.58 mi (805.60 km) |
