| Knowle to Olympia Heights (Florida) | 4,359.77 mi (7,016.37 km) |
| Knowle to Omaha (Nebraska) | 4,200.80 mi (6,760.54 km) |
| Knowle to On Top of the World Designated Place (Florida) | 4,268.69 mi (6,869.80 km) |
| Knowle to Onalaska (Wisconsin) | 3,897.79 mi (6,272.89 km) |
| Knowle to Oneida (New York) | 3,341.46 mi (5,377.55 km) |
| Knowle to Oneonta (New York) | 3,344.50 mi (5,382.45 km) |
| Knowle to Ontario (California) | 5,329.26 mi (8,576.61 km) |
| Knowle to Ontario (Oregon) | 4,746.12 mi (7,638.14 km) |
| Knowle to Opa-locka (Florida) | 4,347.28 mi (6,996.27 km) |
| Knowle to Opelika (Alabama) | 4,216.64 mi (6,786.03 km) |
| Knowle to Opelousas (Louisiana) | 4,593.00 mi (7,391.72 km) |
| Knowle to Orange (California) | 5,349.66 mi (8,609.44 km) |
| Knowle to Orange (Texas) | 4,680.17 mi (7,532.01 km) |
| Knowle to Orange City (Florida) | 4,236.07 mi (6,817.29 km) |
| Knowle to Orangeburg (South Carolina) | 3,992.65 mi (6,425.55 km) |
