| Mering to Olympia Heights (Florida) | 4,970.50 mi (7,999.25 km) |
| Mering to Omaha (Nebraska) | 4,821.82 mi (7,759.96 km) |
| Mering to On Top of the World Designated Place (Florida) | 4,887.97 mi (7,866.42 km) |
| Mering to Onalaska (Wisconsin) | 4,519.99 mi (7,274.22 km) |
| Mering to Oneida (New York) | 3,969.18 mi (6,387.77 km) |
| Mering to Oneonta (New York) | 3,971.82 mi (6,392.03 km) |
| Mering to Ontario (California) | 5,926.76 mi (9,538.21 km) |
| Mering to Ontario (Oregon) | 5,323.39 mi (8,567.17 km) |
| Mering to Opa-locka (Florida) | 4,958.19 mi (7,979.44 km) |
| Mering to Opelika (Alabama) | 4,842.48 mi (7,793.23 km) |
| Mering to Opelousas (Louisiana) | 5,220.69 mi (8,401.89 km) |
| Mering to Orange (California) | 5,947.09 mi (9,570.91 km) |
| Mering to Orange (Texas) | 5,308.09 mi (8,542.54 km) |
| Mering to Orange City (Florida) | 4,853.79 mi (7,811.41 km) |
| Mering to Orangeburg (South Carolina) | 4,615.87 mi (7,428.52 km) |
