| Portchester to Olympia Heights (Florida) | 4,401.69 mi (7,083.84 km) |
| Portchester to Omaha (Nebraska) | 4,278.84 mi (6,886.12 km) |
| Portchester to On Top of the World Designated Place (Florida) | 4,317.65 mi (6,948.59 km) |
| Portchester to Onalaska (Wisconsin) | 3,974.93 mi (6,397.03 km) |
| Portchester to Oneida (New York) | 3,404.09 mi (5,478.35 km) |
| Portchester to Oneonta (New York) | 3,405.53 mi (5,480.68 km) |
| Portchester to Ontario (California) | 5,418.54 mi (8,720.30 km) |
| Portchester to Ontario (Oregon) | 4,841.31 mi (7,791.34 km) |
| Portchester to Opa-locka (Florida) | 4,389.33 mi (7,063.94 km) |
| Portchester to Opelika (Alabama) | 4,273.96 mi (6,878.27 km) |
| Portchester to Opelousas (Louisiana) | 4,655.09 mi (7,491.65 km) |
| Portchester to Orange (California) | 5,438.95 mi (8,753.15 km) |
| Portchester to Orange (Texas) | 4,743.63 mi (7,634.14 km) |
| Portchester to Orange City (Florida) | 4,283.57 mi (6,893.73 km) |
| Portchester to Orangeburg (South Carolina) | 4,046.00 mi (6,511.41 km) |
