| Lombard to Olympia Heights (Florida) | 1,198.46 mi (1,928.74 km) |
| Lombard to Omaha (Nebraska) | 417.45 mi (671.83 km) |
| Lombard to On Top of the World Designated Place (Florida) | 938.64 mi (1,510.59 km) |
| Lombard to Onalaska (Wisconsin) | 213.23 mi (343.17 km) |
| Lombard to Oneida (New York) | 634.41 mi (1,020.99 km) |
| Lombard to Oneonta (New York) | 663.73 mi (1,068.18 km) |
| Lombard to Ontario (California) | 1,690.61 mi (2,720.77 km) |
| Lombard to Ontario (Oregon) | 1,464.53 mi (2,356.93 km) |
| Lombard to Opa-locka (Florida) | 1,188.79 mi (1,913.17 km) |
| Lombard to Opelika (Alabama) | 652.78 mi (1,050.55 km) |
| Lombard to Opelousas (Louisiana) | 815.97 mi (1,313.18 km) |
| Lombard to Orange (California) | 1,709.09 mi (2,750.51 km) |
| Lombard to Orange (Texas) | 872.60 mi (1,404.31 km) |
| Lombard to Orange City (Florida) | 970.17 mi (1,561.33 km) |
| Lombard to Orangeburg (South Carolina) | 698.07 mi (1,123.44 km) |
