| Hilo to Olympia Heights (Florida) | 4,720.66 mi (7,597.17 km) |
| Hilo to Omaha (Nebraska) | 3,738.03 mi (6,015.78 km) |
| Hilo to On Top of the World Designated Place (Florida) | 4,558.39 mi (7,336.02 km) |
| Hilo to Onalaska (Wisconsin) | 3,996.24 mi (6,431.33 km) |
| Hilo to Oneida (New York) | 4,776.10 mi (7,686.40 km) |
| Hilo to Oneonta (New York) | 4,812.12 mi (7,744.36 km) |
| Hilo to Ontario (California) | 2,495.99 mi (4,016.90 km) |
| Hilo to Ontario (Oregon) | 2,758.98 mi (4,440.16 km) |
| Hilo to Opa-locka (Florida) | 4,723.19 mi (7,601.24 km) |
| Hilo to Opelika (Alabama) | 4,340.85 mi (6,985.92 km) |
| Hilo to Opelousas (Louisiana) | 3,963.62 mi (6,378.83 km) |
| Hilo to Orange (California) | 2,480.16 mi (3,991.43 km) |
| Hilo to Orange (Texas) | 3,866.11 mi (6,221.91 km) |
| Hilo to Orange City (Florida) | 4,619.86 mi (7,434.94 km) |
| Hilo to Orangeburg (South Carolina) | 4,591.65 mi (7,389.55 km) |
