| Northbrook to Orbetello | 4,732.49 mi (7,616.20 km) |
| Northbrook to Oria | 5,073.28 mi (8,164.66 km) |
| Northbrook to Oristano | 4,732.22 mi (7,615.77 km) |
| Northbrook to Orta Nova | 4,959.97 mi (7,982.31 km) |
| Northbrook to Orte | 4,778.51 mi (7,690.26 km) |
| Northbrook to Ortona | 4,862.97 mi (7,826.20 km) |
| Northbrook to Orvieto | 4,756.43 mi (7,654.73 km) |
| Northbrook to Orzinuovi | 4,557.97 mi (7,335.34 km) |
| Northbrook to Osimo | 4,777.48 mi (7,688.61 km) |
| Northbrook to Ospitaletto | 4,557.05 mi (7,333.87 km) |
| Northbrook to Ostuni | 5,060.59 mi (8,144.24 km) |
| Northbrook to Ottaviano | 4,932.54 mi (7,938.16 km) |
| Northbrook to Ovada | 4,538.34 mi (7,303.76 km) |
| Northbrook to Ozieri | 4,720.79 mi (7,597.38 km) |
| Northbrook to Paceco | 4,981.19 mi (8,016.46 km) |
