| Merrifield to Olympia Heights (Florida) | 926.16 mi (1,490.52 km) |
| Merrifield to Omaha (Nebraska) | 1,006.16 mi (1,619.26 km) |
| Merrifield to On Top of the World Designated Place (Florida) | 733.78 mi (1,180.90 km) |
| Merrifield to Onalaska (Wisconsin) | 801.23 mi (1,289.46 km) |
| Merrifield to Oneida (New York) | 301.91 mi (485.88 km) |
| Merrifield to Oneonta (New York) | 272.48 mi (438.51 km) |
| Merrifield to Ontario (California) | 2,249.40 mi (3,620.05 km) |
| Merrifield to Ontario (Oregon) | 2,067.75 mi (3,327.72 km) |
| Merrifield to Opa-locka (Florida) | 913.28 mi (1,469.79 km) |
| Merrifield to Opelika (Alabama) | 625.73 mi (1,007.01 km) |
| Merrifield to Opelousas (Louisiana) | 1,019.24 mi (1,640.31 km) |
| Merrifield to Orange (California) | 2,266.69 mi (3,647.88 km) |
| Merrifield to Orange (Texas) | 1,115.40 mi (1,795.06 km) |
| Merrifield to Orange City (Florida) | 724.58 mi (1,166.09 km) |
| Merrifield to Orangeburg (South Carolina) | 423.04 mi (680.82 km) |
