| Hilliard to Olympia Heights (Florida) | 1,002.10 mi (1,612.72 km) |
| Hilliard to Omaha (Nebraska) | 680.64 mi (1,095.39 km) |
| Hilliard to On Top of the World Designated Place (Florida) | 756.77 mi (1,217.90 km) |
| Hilliard to Onalaska (Wisconsin) | 491.49 mi (790.98 km) |
| Hilliard to Oneida (New York) | 440.62 mi (709.10 km) |
| Hilliard to Oneonta (New York) | 452.14 mi (727.65 km) |
| Hilliard to Ontario (California) | 1,931.92 mi (3,109.12 km) |
| Hilliard to Ontario (Oregon) | 1,744.82 mi (2,808.02 km) |
| Hilliard to Opa-locka (Florida) | 990.90 mi (1,594.70 km) |
| Hilliard to Opelika (Alabama) | 524.20 mi (843.62 km) |
| Hilliard to Opelousas (Louisiana) | 826.73 mi (1,330.49 km) |
| Hilliard to Orange (California) | 1,949.59 mi (3,137.57 km) |
| Hilliard to Orange (Texas) | 908.82 mi (1,462.60 km) |
| Hilliard to Orange City (Florida) | 774.27 mi (1,246.07 km) |
| Hilliard to Orangeburg (South Carolina) | 469.44 mi (755.49 km) |
