| Holtsville to Olympia Heights (Florida) | 1,123.36 mi (1,807.88 km) |
| Holtsville to Omaha (Nebraska) | 1,195.98 mi (1,924.74 km) |
| Holtsville to On Top of the World Designated Place (Florida) | 962.06 mi (1,548.29 km) |
| Holtsville to Onalaska (Wisconsin) | 949.37 mi (1,527.87 km) |
| Holtsville to Oneida (New York) | 206.31 mi (332.03 km) |
| Holtsville to Oneonta (New York) | 154.21 mi (248.18 km) |
| Holtsville to Ontario (California) | 2,462.40 mi (3,962.85 km) |
| Holtsville to Ontario (Oregon) | 2,225.15 mi (3,581.04 km) |
| Holtsville to Opa-locka (Florida) | 1,110.18 mi (1,786.66 km) |
| Holtsville to Opelika (Alabama) | 883.58 mi (1,421.98 km) |
| Holtsville to Opelousas (Louisiana) | 1,278.91 mi (2,058.21 km) |
| Holtsville to Orange (California) | 2,480.38 mi (3,991.78 km) |
| Holtsville to Orange (Texas) | 1,374.59 mi (2,212.18 km) |
| Holtsville to Orange City (Florida) | 943.29 mi (1,518.07 km) |
| Holtsville to Orangeburg (South Carolina) | 663.73 mi (1,068.18 km) |
