| Houthulst to Olympia Heights (Florida) | 4,574.22 mi (7,361.50 km) |
| Houthulst to Omaha (Nebraska) | 4,422.22 mi (7,116.87 km) |
| Houthulst to On Top of the World Designated Place (Florida) | 4,486.85 mi (7,220.89 km) |
| Houthulst to Onalaska (Wisconsin) | 4,119.52 mi (6,629.73 km) |
| Houthulst to Oneida (New York) | 3,563.88 mi (5,735.51 km) |
| Houthulst to Oneonta (New York) | 3,566.63 mi (5,739.93 km) |
| Houthulst to Ontario (California) | 5,543.58 mi (8,921.54 km) |
| Houthulst to Ontario (Oregon) | 4,953.60 mi (7,972.05 km) |
| Houthulst to Opa-locka (Florida) | 4,561.81 mi (7,341.52 km) |
| Houthulst to Opelika (Alabama) | 4,437.93 mi (7,142.16 km) |
| Houthulst to Opelousas (Louisiana) | 4,815.40 mi (7,749.63 km) |
| Houthulst to Orange (California) | 5,563.97 mi (8,954.34 km) |
| Houthulst to Orange (Texas) | 4,902.78 mi (7,890.26 km) |
| Houthulst to Orange City (Florida) | 4,453.53 mi (7,167.26 km) |
| Houthulst to Orangeburg (South Carolina) | 4,212.61 mi (6,779.55 km) |
