| Ardea to Olympia Heights (Florida) | 5,200.43 mi (8,369.28 km) |
| Ardea to Omaha (Nebraska) | 5,182.33 mi (8,340.15 km) |
| Ardea to On Top of the World Designated Place (Florida) | 5,144.40 mi (8,279.11 km) |
| Ardea to Onalaska (Wisconsin) | 4,877.45 mi (7,849.50 km) |
| Ardea to Oneida (New York) | 4,278.57 mi (6,885.70 km) |
| Ardea to Oneonta (New York) | 4,275.83 mi (6,881.29 km) |
| Ardea to Ontario (California) | 6,328.24 mi (10,184.31 km) |
| Ardea to Ontario (Oregon) | 5,744.36 mi (9,244.65 km) |
| Ardea to Opa-locka (Florida) | 5,188.70 mi (8,350.40 km) |
| Ardea to Opelika (Alabama) | 5,129.44 mi (8,255.04 km) |
| Ardea to Opelousas (Louisiana) | 5,523.41 mi (8,889.07 km) |
| Ardea to Orange (California) | 6,348.64 mi (10,217.16 km) |
| Ardea to Orange (Texas) | 5,615.55 mi (9,037.35 km) |
| Ardea to Orange City (Florida) | 5,105.12 mi (8,215.90 km) |
| Ardea to Orangeburg (South Carolina) | 4,889.84 mi (7,869.44 km) |
