| Highlands Ranch to Oerlinghausen | 4,966.66 mi (7,993.07 km) |
| Highlands Ranch to Oestrich-Winkel | 5,036.05 mi (8,104.73 km) |
| Highlands Ranch to Offenburg | 5,104.94 mi (8,215.61 km) |
| Highlands Ranch to Oftersheim | 5,084.64 mi (8,182.94 km) |
| Highlands Ranch to Ohrdruf | 5,085.45 mi (8,184.25 km) |
| Highlands Ranch to Ohringen | 5,122.90 mi (8,244.52 km) |
| Highlands Ranch to Olbernhau | 5,174.42 mi (8,327.43 km) |
| Highlands Ranch to Olching | 5,230.51 mi (8,417.70 km) |
| Highlands Ranch to Oldenburg | 4,898.36 mi (7,883.15 km) |
| Highlands Ranch to Oldenburg in Holstein | 4,925.70 mi (7,927.15 km) |
| Highlands Ranch to Olfen | 4,937.16 mi (7,945.59 km) |
| Highlands Ranch to Olpe | 4,983.72 mi (8,020.53 km) |
| Highlands Ranch to Olsberg | 4,989.33 mi (8,029.55 km) |
| Highlands Ranch to Oranienburg | 5,069.38 mi (8,158.38 km) |
| Highlands Ranch to Ortenberg | 5,054.02 mi (8,133.67 km) |
