| Buffalo Grove to Oerlinghausen | 4,254.27 mi (6,846.59 km) |
| Buffalo Grove to Oestrich-Winkel | 4,304.86 mi (6,928.00 km) |
| Buffalo Grove to Offenburg | 4,361.53 mi (7,019.20 km) |
| Buffalo Grove to Oftersheim | 4,350.82 mi (7,001.98 km) |
| Buffalo Grove to Ohrdruf | 4,372.10 mi (7,036.22 km) |
| Buffalo Grove to Ohringen | 4,391.49 mi (7,067.42 km) |
| Buffalo Grove to Olbernhau | 4,470.94 mi (7,195.28 km) |
| Buffalo Grove to Olching | 4,499.06 mi (7,240.53 km) |
| Buffalo Grove to Oldenburg | 4,194.27 mi (6,750.03 km) |
| Buffalo Grove to Oldenburg in Holstein | 4,242.52 mi (6,827.68 km) |
| Buffalo Grove to Olfen | 4,217.60 mi (6,787.57 km) |
| Buffalo Grove to Olpe | 4,260.11 mi (6,855.98 km) |
| Buffalo Grove to Olsberg | 4,271.05 mi (6,873.60 km) |
| Buffalo Grove to Oranienburg | 4,382.69 mi (7,053.25 km) |
| Buffalo Grove to Ortenberg | 4,329.93 mi (6,968.35 km) |
