| Highgate to Orbetello | 825.39 mi (1,328.34 km) |
| Highgate to Oria | 1,140.06 mi (1,834.74 km) |
| Highgate to Oristano | 907.98 mi (1,461.26 km) |
| Highgate to Orta Nova | 1,030.49 mi (1,658.42 km) |
| Highgate to Orte | 860.66 mi (1,385.10 km) |
| Highgate to Ortona | 933.02 mi (1,501.55 km) |
| Highgate to Orvieto | 837.98 mi (1,348.60 km) |
| Highgate to Orzinuovi | 627.33 mi (1,009.58 km) |
| Highgate to Osimo | 844.07 mi (1,358.40 km) |
| Highgate to Ospitaletto | 624.34 mi (1,004.77 km) |
| Highgate to Ostuni | 1,126.35 mi (1,812.68 km) |
| Highgate to Ottaviano | 1,014.93 mi (1,633.37 km) |
| Highgate to Ovada | 626.75 mi (1,008.65 km) |
| Highgate to Ozieri | 875.08 mi (1,408.31 km) |
| Highgate to Paceco | 1,123.00 mi (1,807.29 km) |
