| Harstad to Olympia Heights (Florida) | 4,736.62 mi (7,622.85 km) |
| Harstad to Omaha (Nebraska) | 4,097.71 mi (6,594.63 km) |
| Harstad to On Top of the World Designated Place (Florida) | 4,567.66 mi (7,350.93 km) |
| Harstad to Onalaska (Wisconsin) | 3,832.37 mi (6,167.61 km) |
| Harstad to Oneida (New York) | 3,537.63 mi (5,693.26 km) |
| Harstad to Oneonta (New York) | 3,561.74 mi (5,732.07 km) |
| Harstad to Ontario (California) | 4,957.44 mi (7,978.23 km) |
| Harstad to Ontario (Oregon) | 4,286.29 mi (6,898.11 km) |
| Harstad to Opa-locka (Florida) | 4,723.41 mi (7,601.59 km) |
| Harstad to Opelika (Alabama) | 4,413.61 mi (7,103.02 km) |
| Harstad to Opelousas (Louisiana) | 4,700.67 mi (7,565.00 km) |
| Harstad to Orange (California) | 4,976.46 mi (8,008.84 km) |
| Harstad to Orange (Texas) | 4,763.25 mi (7,665.71 km) |
| Harstad to Orange City (Florida) | 4,554.90 mi (7,330.41 km) |
| Harstad to Orangeburg (South Carolina) | 4,256.29 mi (6,849.84 km) |
