| Port Neches to Orbetello | 5,542.11 mi (8,919.17 km) |
| Port Neches to Oria | 5,892.47 mi (9,483.02 km) |
| Port Neches to Oristano | 5,516.84 mi (8,878.50 km) |
| Port Neches to Orta Nova | 5,777.44 mi (9,297.89 km) |
| Port Neches to Orte | 5,591.91 mi (8,999.30 km) |
| Port Neches to Ortona | 5,681.97 mi (9,144.24 km) |
| Port Neches to Orvieto | 5,570.49 mi (8,964.83 km) |
| Port Neches to Orzinuovi | 5,381.39 mi (8,660.50 km) |
| Port Neches to Osimo | 5,600.02 mi (9,012.37 km) |
| Port Neches to Ospitaletto | 5,381.74 mi (8,661.07 km) |
| Port Neches to Ostuni | 5,880.87 mi (9,464.34 km) |
| Port Neches to Ottaviano | 5,743.28 mi (9,242.92 km) |
| Port Neches to Ovada | 5,353.69 mi (8,615.93 km) |
| Port Neches to Ozieri | 5,511.41 mi (8,869.76 km) |
| Port Neches to Paceco | 5,767.58 mi (9,282.03 km) |
