| Ridge to Orbetello | 4,148.90 mi (6,677.02 km) |
| Ridge to Oria | 4,502.00 mi (7,245.26 km) |
| Ridge to Oristano | 4,117.87 mi (6,627.07 km) |
| Ridge to Orta Nova | 4,386.58 mi (7,059.52 km) |
| Ridge to Orte | 4,199.95 mi (6,759.17 km) |
| Ridge to Ortona | 4,292.07 mi (6,907.42 km) |
| Ridge to Orvieto | 4,178.86 mi (6,725.22 km) |
| Ridge to Orzinuovi | 3,994.74 mi (6,428.92 km) |
| Ridge to Osimo | 4,212.09 mi (6,778.70 km) |
| Ridge to Ospitaletto | 3,995.78 mi (6,430.59 km) |
| Ridge to Ostuni | 4,490.90 mi (7,227.41 km) |
| Ridge to Ottaviano | 4,349.93 mi (7,000.54 km) |
| Ridge to Ovada | 3,963.29 mi (6,378.30 km) |
| Ridge to Ozieri | 4,113.35 mi (6,619.79 km) |
| Ridge to Paceco | 4,368.59 mi (7,030.57 km) |
