| Sinop to Orbetello | 1,220.91 mi (1,964.87 km) |
| Sinop to Oria | 914.28 mi (1,471.39 km) |
| Sinop to Oristano | 1,387.77 mi (2,233.40 km) |
| Sinop to Orta Nova | 1,002.17 mi (1,612.84 km) |
| Sinop to Orte | 1,161.30 mi (1,868.94 km) |
| Sinop to Ortona | 1,059.93 mi (1,705.79 km) |
| Sinop to Orvieto | 1,173.43 mi (1,888.45 km) |
| Sinop to Orzinuovi | 1,275.30 mi (2,052.40 km) |
| Sinop to Osimo | 1,100.73 mi (1,771.45 km) |
| Sinop to Ospitaletto | 1,268.86 mi (2,042.04 km) |
| Sinop to Ostuni | 913.53 mi (1,470.18 km) |
| Sinop to Ottaviano | 1,071.30 mi (1,724.09 km) |
| Sinop to Ovada | 1,338.20 mi (2,153.63 km) |
| Sinop to Ozieri | 1,355.50 mi (2,181.47 km) |
| Sinop to Paceco | 1,224.45 mi (1,970.55 km) |
