| Leiden to Olympia Heights (Florida) | 4,621.28 mi (7,437.24 km) |
| Leiden to Omaha (Nebraska) | 4,430.38 mi (7,130.01 km) |
| Leiden to On Top of the World Designated Place (Florida) | 4,527.41 mi (7,286.16 km) |
| Leiden to Onalaska (Wisconsin) | 4,129.17 mi (6,645.25 km) |
| Leiden to Oneida (New York) | 3,591.12 mi (5,779.36 km) |
| Leiden to Oneonta (New York) | 3,595.58 mi (5,786.53 km) |
| Leiden to Ontario (California) | 5,534.28 mi (8,906.57 km) |
| Leiden to Ontario (Oregon) | 4,934.76 mi (7,941.73 km) |
| Leiden to Opa-locka (Florida) | 4,608.75 mi (7,417.07 km) |
| Leiden to Opelika (Alabama) | 4,470.19 mi (7,194.07 km) |
| Leiden to Opelousas (Louisiana) | 4,842.35 mi (7,793.01 km) |
| Leiden to Orange (California) | 5,554.62 mi (8,939.29 km) |
| Leiden to Orange (Texas) | 4,928.16 mi (7,931.11 km) |
| Leiden to Orange City (Florida) | 4,495.49 mi (7,234.79 km) |
| Leiden to Orangeburg (South Carolina) | 4,249.02 mi (6,838.13 km) |
