| Cobh to Olympia Heights (Florida) | 4,086.35 mi (6,576.34 km) |
| Cobh to Omaha (Nebraska) | 3,975.09 mi (6,397.30 km) |
| Cobh to On Top of the World Designated Place (Florida) | 4,000.58 mi (6,438.31 km) |
| Cobh to Onalaska (Wisconsin) | 3,670.33 mi (5,906.83 km) |
| Cobh to Oneida (New York) | 3,088.78 mi (4,970.92 km) |
| Cobh to Oneonta (New York) | 3,089.63 mi (4,972.28 km) |
| Cobh to Ontario (California) | 5,132.24 mi (8,259.54 km) |
| Cobh to Ontario (Oregon) | 4,570.74 mi (7,355.90 km) |
| Cobh to Opa-locka (Florida) | 4,073.94 mi (6,556.37 km) |
| Cobh to Opelika (Alabama) | 3,957.01 mi (6,368.19 km) |
| Cobh to Opelousas (Louisiana) | 4,339.34 mi (6,983.49 km) |
| Cobh to Orange (California) | 5,152.67 mi (8,292.42 km) |
| Cobh to Orange (Texas) | 4,428.39 mi (7,126.80 km) |
| Cobh to Orange City (Florida) | 3,966.72 mi (6,383.81 km) |
| Cobh to Orangeburg (South Carolina) | 3,728.68 mi (6,000.73 km) |
