| Houghton le Spring to Olympia Heights (Florida) | 4,348.46 mi (6,998.17 km) |
| Houghton le Spring to Omaha (Nebraska) | 4,124.59 mi (6,637.89 km) |
| Houghton le Spring to On Top of the World Designated Place (Florida) | 4,245.63 mi (6,832.68 km) |
| Houghton le Spring to Onalaska (Wisconsin) | 3,823.83 mi (6,153.86 km) |
| Houghton le Spring to Oneida (New York) | 3,296.13 mi (5,304.60 km) |
| Houghton le Spring to Oneonta (New York) | 3,302.09 mi (5,314.20 km) |
| Houghton le Spring to Ontario (California) | 5,228.64 mi (8,414.68 km) |
| Houghton le Spring to Ontario (Oregon) | 4,632.89 mi (7,455.92 km) |
| Houghton le Spring to Opa-locka (Florida) | 4,335.77 mi (6,977.75 km) |
| Houghton le Spring to Opelika (Alabama) | 4,179.10 mi (6,725.62 km) |
| Houghton le Spring to Opelousas (Louisiana) | 4,546.27 mi (7,316.51 km) |
| Houghton le Spring to Orange (California) | 5,248.99 mi (8,447.43 km) |
| Houghton le Spring to Orange (Texas) | 4,630.82 mi (7,452.58 km) |
| Houghton le Spring to Orange City (Florida) | 4,215.57 mi (6,784.30 km) |
| Houghton le Spring to Orangeburg (South Carolina) | 3,962.52 mi (6,377.07 km) |
