| Calexico to Orbetello | 6,245.53 mi (10,051.21 km) |
| Calexico to Oria | 6,562.47 mi (10,561.28 km) |
| Calexico to Oristano | 6,279.36 mi (10,105.66 km) |
| Calexico to Orta Nova | 6,454.92 mi (10,388.20 km) |
| Calexico to Orte | 6,284.52 mi (10,113.97 km) |
| Calexico to Ortona | 6,357.61 mi (10,231.59 km) |
| Calexico to Orvieto | 6,261.88 mi (10,077.53 km) |
| Calexico to Orzinuovi | 6,052.33 mi (9,740.28 km) |
| Calexico to Osimo | 6,267.96 mi (10,087.31 km) |
| Calexico to Ospitaletto | 6,049.17 mi (9,735.20 km) |
| Calexico to Ostuni | 6,548.17 mi (10,538.26 km) |
| Calexico to Ottaviano | 6,439.31 mi (10,363.06 km) |
| Calexico to Ovada | 6,046.80 mi (9,731.38 km) |
| Calexico to Ozieri | 6,260.74 mi (10,075.69 km) |
| Calexico to Paceco | 6,521.46 mi (10,495.27 km) |
