| Millbrook to Olympia Heights (Florida) | 593.08 mi (954.47 km) |
| Millbrook to Omaha (Nebraska) | 806.68 mi (1,298.23 km) |
| Millbrook to On Top of the World Designated Place (Florida) | 337.45 mi (543.08 km) |
| Millbrook to Onalaska (Wisconsin) | 828.90 mi (1,333.99 km) |
| Millbrook to Oneida (New York) | 934.21 mi (1,503.47 km) |
| Millbrook to Oneonta (New York) | 924.17 mi (1,487.31 km) |
| Millbrook to Ontario (California) | 1,800.40 mi (2,897.46 km) |
| Millbrook to Ontario (Oregon) | 1,826.97 mi (2,940.22 km) |
| Millbrook to Opa-locka (Florida) | 586.51 mi (943.90 km) |
| Millbrook to Opelika (Alabama) | 59.06 mi (95.04 km) |
| Millbrook to Opelousas (Louisiana) | 362.85 mi (583.94 km) |
| Millbrook to Orange (California) | 1,814.31 mi (2,919.84 km) |
| Millbrook to Orange (Texas) | 465.89 mi (749.78 km) |
| Millbrook to Orange City (Florida) | 389.80 mi (627.32 km) |
| Millbrook to Orangeburg (South Carolina) | 326.30 mi (525.13 km) |
