| Glendale Heights to Oerlinghausen | 4,270.76 mi (6,873.12 km) |
| Glendale Heights to Oestrich-Winkel | 4,321.06 mi (6,954.07 km) |
| Glendale Heights to Offenburg | 4,377.51 mi (7,044.92 km) |
| Glendale Heights to Oftersheim | 4,366.97 mi (7,027.96 km) |
| Glendale Heights to Ohrdruf | 4,388.55 mi (7,062.69 km) |
| Glendale Heights to Ohringen | 4,407.66 mi (7,093.45 km) |
| Glendale Heights to Olbernhau | 4,487.51 mi (7,221.95 km) |
| Glendale Heights to Olching | 4,515.22 mi (7,266.54 km) |
| Glendale Heights to Oldenburg | 4,210.89 mi (6,776.77 km) |
| Glendale Heights to Oldenburg in Holstein | 4,259.39 mi (6,854.82 km) |
| Glendale Heights to Olfen | 4,233.99 mi (6,813.94 km) |
| Glendale Heights to Olpe | 4,276.43 mi (6,882.25 km) |
| Glendale Heights to Olsberg | 4,287.45 mi (6,899.99 km) |
| Glendale Heights to Oranienburg | 4,399.49 mi (7,080.30 km) |
| Glendale Heights to Ortenberg | 4,346.24 mi (6,994.59 km) |
