| Northbrook to Oerlinghausen | 4,251.67 mi (6,842.40 km) |
| Northbrook to Oestrich-Winkel | 4,302.02 mi (6,923.43 km) |
| Northbrook to Offenburg | 4,358.52 mi (7,014.36 km) |
| Northbrook to Oftersheim | 4,347.94 mi (6,997.34 km) |
| Northbrook to Ohrdruf | 4,369.47 mi (7,031.98 km) |
| Northbrook to Ohringen | 4,388.63 mi (7,062.82 km) |
| Northbrook to Olbernhau | 4,468.41 mi (7,191.21 km) |
| Northbrook to Olching | 4,496.19 mi (7,235.91 km) |
| Northbrook to Oldenburg | 4,191.78 mi (6,746.02 km) |
| Northbrook to Oldenburg in Holstein | 4,240.26 mi (6,824.05 km) |
| Northbrook to Olfen | 4,214.91 mi (6,783.24 km) |
| Northbrook to Olpe | 4,257.37 mi (6,851.57 km) |
| Northbrook to Olsberg | 4,268.37 mi (6,869.29 km) |
| Northbrook to Oranienburg | 4,380.37 mi (7,049.52 km) |
| Northbrook to Ortenberg | 4,327.18 mi (6,963.92 km) |
