| Euclid to Oerlinghausen | 4,047.28 mi (6,513.47 km) |
| Euclid to Oestrich-Winkel | 4,088.04 mi (6,579.07 km) |
| Euclid to Offenburg | 4,138.08 mi (6,659.60 km) |
| Euclid to Oftersheim | 4,132.32 mi (6,650.32 km) |
| Euclid to Ohrdruf | 4,163.62 mi (6,700.69 km) |
| Euclid to Ohringen | 4,173.86 mi (6,717.19 km) |
| Euclid to Olbernhau | 4,266.45 mi (6,866.19 km) |
| Euclid to Olching | 4,280.58 mi (6,888.93 km) |
| Euclid to Oldenburg | 3,991.95 mi (6,424.42 km) |
| Euclid to Oldenburg in Holstein | 4,049.99 mi (6,517.82 km) |
| Euclid to Olfen | 4,007.35 mi (6,449.21 km) |
| Euclid to Olpe | 4,047.47 mi (6,513.77 km) |
| Euclid to Olsberg | 4,060.99 mi (6,535.53 km) |
| Euclid to Oranienburg | 4,187.13 mi (6,738.53 km) |
| Euclid to Ortenberg | 4,116.47 mi (6,624.82 km) |
