| Vacaville to Orbetello | 6,128.19 mi (9,862.37 km) |
| Vacaville to Oria | 6,420.57 mi (10,332.90 km) |
| Vacaville to Oristano | 6,190.69 mi (9,962.96 km) |
| Vacaville to Orta Nova | 6,319.46 mi (10,170.18 km) |
| Vacaville to Orte | 6,160.89 mi (9,914.99 km) |
| Vacaville to Ortona | 6,223.86 mi (10,016.33 km) |
| Vacaville to Orvieto | 6,138.26 mi (9,878.58 km) |
| Vacaville to Orzinuovi | 5,924.52 mi (9,534.59 km) |
| Vacaville to Osimo | 6,132.93 mi (9,870.00 km) |
| Vacaville to Ospitaletto | 5,919.78 mi (9,526.96 km) |
| Vacaville to Ostuni | 6,405.36 mi (10,308.43 km) |
| Vacaville to Ottaviano | 6,313.20 mi (10,160.12 km) |
| Vacaville to Ovada | 5,929.77 mi (9,543.04 km) |
| Vacaville to Ozieri | 6,165.84 mi (9,922.96 km) |
| Vacaville to Paceco | 6,421.99 mi (10,335.19 km) |
