| San Francisco to Orbetello | 6,177.29 mi (9,941.38 km) |
| San Francisco to Oria | 6,469.61 mi (10,411.84 km) |
| San Francisco to Oristano | 6,239.69 mi (10,041.82 km) |
| San Francisco to Orta Nova | 6,368.53 mi (10,249.16 km) |
| San Francisco to Orte | 6,209.98 mi (9,994.00 km) |
| San Francisco to Ortona | 6,272.94 mi (10,095.32 km) |
| San Francisco to Orvieto | 6,187.36 mi (9,957.59 km) |
| San Francisco to Orzinuovi | 5,973.61 mi (9,613.60 km) |
| San Francisco to Osimo | 6,182.01 mi (9,948.98 km) |
| San Francisco to Ospitaletto | 5,968.87 mi (9,605.97 km) |
| San Francisco to Ostuni | 6,454.40 mi (10,387.36 km) |
| San Francisco to Ottaviano | 6,362.30 mi (10,239.13 km) |
| San Francisco to Ovada | 5,978.86 mi (9,622.05 km) |
| San Francisco to Ozieri | 6,214.87 mi (10,001.87 km) |
| San Francisco to Paceco | 6,471.05 mi (10,414.15 km) |
