| Barth to Olympia Heights (Florida) | 4,908.87 mi (7,900.07 km) |
| Barth to Omaha (Nebraska) | 4,610.37 mi (7,419.68 km) |
| Barth to On Top of the World Designated Place (Florida) | 4,798.83 mi (7,722.97 km) |
| Barth to Onalaska (Wisconsin) | 4,315.36 mi (6,944.90 km) |
| Barth to Oneida (New York) | 3,831.16 mi (6,165.66 km) |
| Barth to Oneonta (New York) | 3,840.23 mi (6,180.25 km) |
| Barth to Ontario (California) | 5,652.13 mi (9,096.23 km) |
| Barth to Ontario (Oregon) | 5,023.32 mi (8,084.26 km) |
| Barth to Opa-locka (Florida) | 4,896.10 mi (7,879.51 km) |
| Barth to Opelika (Alabama) | 4,719.83 mi (7,595.83 km) |
| Barth to Opelousas (Louisiana) | 5,075.80 mi (8,168.71 km) |
| Barth to Orange (California) | 5,672.21 mi (9,128.54 km) |
| Barth to Orange (Texas) | 5,156.82 mi (8,299.10 km) |
| Barth to Orange City (Florida) | 4,770.62 mi (7,677.58 km) |
| Barth to Orangeburg (South Carolina) | 4,510.61 mi (7,259.13 km) |
