| Olbia to Olympia Heights (Florida) | 5,069.37 mi (8,158.36 km) |
| Olbia to Omaha (Nebraska) | 5,096.36 mi (8,201.81 km) |
| Olbia to On Top of the World Designated Place (Florida) | 5,020.47 mi (8,079.67 km) |
| Olbia to Onalaska (Wisconsin) | 4,790.72 mi (7,709.92 km) |
| Olbia to Oneida (New York) | 4,173.54 mi (6,716.66 km) |
| Olbia to Oneonta (New York) | 4,168.88 mi (6,709.16 km) |
| Olbia to Ontario (California) | 6,262.55 mi (10,078.60 km) |
| Olbia to Ontario (Oregon) | 5,693.60 mi (9,162.96 km) |
| Olbia to Opa-locka (Florida) | 5,057.80 mi (8,139.74 km) |
| Olbia to Opelika (Alabama) | 5,014.77 mi (8,070.50 km) |
| Olbia to Opelousas (Louisiana) | 5,413.26 mi (8,711.80 km) |
| Olbia to Orange (California) | 6,282.97 mi (10,111.47 km) |
| Olbia to Orange (Texas) | 5,506.88 mi (8,862.47 km) |
| Olbia to Orange City (Florida) | 4,979.85 mi (8,014.30 km) |
| Olbia to Orangeburg (South Carolina) | 4,771.58 mi (7,679.12 km) |
