| Berkhampstead to Orbetello | 847.17 mi (1,363.39 km) |
| Berkhampstead to Oria | 1,162.10 mi (1,870.22 km) |
| Berkhampstead to Oristano | 928.34 mi (1,494.02 km) |
| Berkhampstead to Orta Nova | 1,052.54 mi (1,693.90 km) |
| Berkhampstead to Orte | 882.60 mi (1,420.41 km) |
| Berkhampstead to Ortona | 955.06 mi (1,537.02 km) |
| Berkhampstead to Orvieto | 859.92 mi (1,383.91 km) |
| Berkhampstead to Orzinuovi | 649.35 mi (1,045.03 km) |
| Berkhampstead to Osimo | 866.11 mi (1,393.88 km) |
| Berkhampstead to Ospitaletto | 646.38 mi (1,040.24 km) |
| Berkhampstead to Ostuni | 1,148.38 mi (1,848.15 km) |
| Berkhampstead to Ottaviano | 1,036.90 mi (1,668.73 km) |
| Berkhampstead to Ovada | 648.47 mi (1,043.61 km) |
| Berkhampstead to Ozieri | 895.80 mi (1,441.65 km) |
| Berkhampstead to Paceco | 1,144.27 mi (1,841.52 km) |
