| Allentown to Orbetello | 4,274.74 mi (6,879.53 km) |
| Allentown to Oria | 4,626.82 mi (7,446.15 km) |
| Allentown to Oristano | 4,246.97 mi (6,834.84 km) |
| Allentown to Orta Nova | 4,511.52 mi (7,260.59 km) |
| Allentown to Orte | 4,325.28 mi (6,960.87 km) |
| Allentown to Ortona | 4,416.63 mi (7,107.88 km) |
| Allentown to Orvieto | 4,304.05 mi (6,926.70 km) |
| Allentown to Orzinuovi | 4,118.08 mi (6,627.41 km) |
| Allentown to Osimo | 4,335.93 mi (6,978.01 km) |
| Allentown to Ospitaletto | 4,118.89 mi (6,628.71 km) |
| Allentown to Ostuni | 4,615.53 mi (7,427.98 km) |
| Allentown to Ottaviano | 4,475.86 mi (7,203.21 km) |
| Allentown to Ovada | 4,087.96 mi (6,578.94 km) |
| Allentown to Ozieri | 4,241.73 mi (6,826.40 km) |
| Allentown to Paceco | 4,497.72 mi (7,238.37 km) |
