| Buffalo Grove to Orbetello | 4,735.91 mi (7,621.71 km) |
| Buffalo Grove to Oria | 5,076.52 mi (8,169.87 km) |
| Buffalo Grove to Oristano | 4,736.00 mi (7,621.85 km) |
| Buffalo Grove to Orta Nova | 4,963.25 mi (7,987.58 km) |
| Buffalo Grove to Orte | 4,781.86 mi (7,695.66 km) |
| Buffalo Grove to Ortona | 4,866.23 mi (7,831.44 km) |
| Buffalo Grove to Orvieto | 4,759.77 mi (7,660.12 km) |
| Buffalo Grove to Orzinuovi | 4,561.18 mi (7,340.51 km) |
| Buffalo Grove to Osimo | 4,780.69 mi (7,693.77 km) |
| Buffalo Grove to Ospitaletto | 4,560.24 mi (7,339.00 km) |
| Buffalo Grove to Ostuni | 5,063.82 mi (8,149.42 km) |
| Buffalo Grove to Ottaviano | 4,935.93 mi (7,943.61 km) |
| Buffalo Grove to Ovada | 4,541.69 mi (7,309.14 km) |
| Buffalo Grove to Ozieri | 4,724.49 mi (7,603.33 km) |
| Buffalo Grove to Paceco | 4,984.93 mi (8,022.47 km) |
