| Knightdale to Orbetello | 4,599.28 mi (7,401.82 km) |
| Knightdale to Oria | 4,954.15 mi (7,972.94 km) |
| Knightdale to Oristano | 4,559.91 mi (7,338.46 km) |
| Knightdale to Orta Nova | 4,838.59 mi (7,786.96 km) |
| Knightdale to Orte | 4,651.34 mi (7,485.61 km) |
| Knightdale to Ortona | 4,744.88 mi (7,636.14 km) |
| Knightdale to Orvieto | 4,630.53 mi (7,452.12 km) |
| Knightdale to Orzinuovi | 4,449.89 mi (7,161.41 km) |
| Knightdale to Osimo | 4,666.24 mi (7,509.58 km) |
| Knightdale to Ospitaletto | 4,451.29 mi (7,163.66 km) |
| Knightdale to Ostuni | 4,943.43 mi (7,955.68 km) |
| Knightdale to Ottaviano | 4,799.94 mi (7,724.75 km) |
| Knightdale to Ovada | 4,416.14 mi (7,107.09 km) |
| Knightdale to Ozieri | 4,557.51 mi (7,334.60 km) |
| Knightdale to Paceco | 4,810.27 mi (7,741.38 km) |
