| Darien to Olympia Heights (Florida) | 1,189.60 mi (1,914.47 km) |
| Darien to Omaha (Nebraska) | 418.79 mi (673.97 km) |
| Darien to On Top of the World Designated Place (Florida) | 929.71 mi (1,496.22 km) |
| Darien to Onalaska (Wisconsin) | 220.55 mi (354.93 km) |
| Darien to Oneida (New York) | 634.59 mi (1,021.28 km) |
| Darien to Oneonta (New York) | 663.30 mi (1,067.47 km) |
| Darien to Ontario (California) | 1,690.95 mi (2,721.32 km) |
| Darien to Ontario (Oregon) | 1,468.62 mi (2,363.52 km) |
| Darien to Opa-locka (Florida) | 1,179.93 mi (1,898.92 km) |
| Darien to Opelika (Alabama) | 643.69 mi (1,035.92 km) |
| Darien to Opelousas (Louisiana) | 807.97 mi (1,300.31 km) |
| Darien to Orange (California) | 1,709.39 mi (2,750.99 km) |
| Darien to Orange (Texas) | 865.09 mi (1,392.23 km) |
| Darien to Orange City (Florida) | 961.34 mi (1,547.13 km) |
| Darien to Orangeburg (South Carolina) | 689.86 mi (1,110.22 km) |
