| Hertford to Oerlinghausen | 372.90 mi (600.12 km) |
| Hertford to Oestrich-Winkel | 373.00 mi (600.28 km) |
| Hertford to Offenburg | 422.50 mi (679.95 km) |
| Hertford to Oftersheim | 415.00 mi (667.88 km) |
| Hertford to Ohrdruf | 471.20 mi (758.32 km) |
| Hertford to Ohringen | 457.12 mi (735.66 km) |
| Hertford to Olbernhau | 584.58 mi (940.79 km) |
| Hertford to Olching | 562.95 mi (905.97 km) |
| Hertford to Oldenburg | 360.95 mi (580.89 km) |
| Hertford to Oldenburg in Holstein | 486.37 mi (782.74 km) |
| Hertford to Olfen | 318.99 mi (513.37 km) |
| Hertford to Olpe | 345.00 mi (555.23 km) |
| Hertford to Olsberg | 368.69 mi (593.36 km) |
| Hertford to Oranienburg | 565.92 mi (910.76 km) |
| Hertford to Ortenberg | 408.46 mi (657.35 km) |
