| Pacific Grove to Orbetello | 6,228.28 mi (10,023.44 km) |
| Pacific Grove to Oria | 6,523.96 mi (10,499.31 km) |
| Pacific Grove to Oristano | 6,287.04 mi (10,118.02 km) |
| Pacific Grove to Orta Nova | 6,421.99 mi (10,335.19 km) |
| Pacific Grove to Orte | 6,261.81 mi (10,077.40 km) |
| Pacific Grove to Ortona | 6,326.09 mi (10,180.86 km) |
| Pacific Grove to Orvieto | 6,239.15 mi (10,040.95 km) |
| Pacific Grove to Orzinuovi | 6,025.74 mi (9,697.48 km) |
| Pacific Grove to Osimo | 6,235.24 mi (10,034.64 km) |
| Pacific Grove to Ospitaletto | 6,021.19 mi (9,690.17 km) |
| Pacific Grove to Ostuni | 6,508.85 mi (10,474.98 km) |
| Pacific Grove to Ottaviano | 6,414.57 mi (10,323.26 km) |
| Pacific Grove to Ovada | 6,029.62 mi (9,703.74 km) |
| Pacific Grove to Ozieri | 6,263.01 mi (10,079.34 km) |
| Pacific Grove to Paceco | 6,520.03 mi (10,492.98 km) |
