| Pittsburg to Orbetello | 6,145.94 mi (9,890.94 km) |
| Pittsburg to Oria | 6,439.12 mi (10,362.77 km) |
| Pittsburg to Oristano | 6,207.56 mi (9,990.11 km) |
| Pittsburg to Orta Nova | 6,337.80 mi (10,199.70 km) |
| Pittsburg to Orte | 6,178.84 mi (9,943.88 km) |
| Pittsburg to Ortona | 6,242.13 mi (10,045.74 km) |
| Pittsburg to Orvieto | 6,156.21 mi (9,907.46 km) |
| Pittsburg to Orzinuovi | 5,942.54 mi (9,563.59 km) |
| Pittsburg to Osimo | 6,151.22 mi (9,899.43 km) |
| Pittsburg to Ospitaletto | 5,937.84 mi (9,556.04 km) |
| Pittsburg to Ostuni | 6,423.94 mi (10,338.33 km) |
| Pittsburg to Ottaviano | 6,331.27 mi (10,189.19 km) |
| Pittsburg to Ovada | 5,947.46 mi (9,571.51 km) |
| Pittsburg to Ozieri | 6,182.90 mi (9,950.42 km) |
| Pittsburg to Paceco | 6,439.26 mi (10,362.99 km) |
