| Gurnee to Oerlinghausen | 4,243.40 mi (6,829.09 km) |
| Gurnee to Oestrich-Winkel | 4,294.33 mi (6,911.05 km) |
| Gurnee to Offenburg | 4,351.23 mi (7,002.63 km) |
| Gurnee to Oftersheim | 4,340.35 mi (6,985.11 km) |
| Gurnee to Ohrdruf | 4,361.26 mi (7,018.78 km) |
| Gurnee to Ohringen | 4,380.97 mi (7,050.50 km) |
| Gurnee to Olbernhau | 4,459.96 mi (7,177.61 km) |
| Gurnee to Olching | 4,488.56 mi (7,223.65 km) |
| Gurnee to Oldenburg | 4,183.25 mi (6,732.29 km) |
| Gurnee to Oldenburg in Holstein | 4,231.18 mi (6,809.43 km) |
| Gurnee to Olfen | 4,206.84 mi (6,770.25 km) |
| Gurnee to Olpe | 4,249.43 mi (6,838.80 km) |
| Gurnee to Olsberg | 4,260.28 mi (6,856.26 km) |
| Gurnee to Oranienburg | 4,371.43 mi (7,035.14 km) |
| Gurnee to Ortenberg | 4,319.28 mi (6,951.20 km) |
