| Llanelli to Olympia Heights (Florida) | 4,263.41 mi (6,861.30 km) |
| Llanelli to Omaha (Nebraska) | 4,136.06 mi (6,656.34 km) |
| Llanelli to On Top of the World Designated Place (Florida) | 4,176.91 mi (6,722.09 km) |
| Llanelli to Onalaska (Wisconsin) | 3,831.98 mi (6,166.97 km) |
| Llanelli to Oneida (New York) | 3,260.50 mi (5,247.27 km) |
| Llanelli to Oneonta (New York) | 3,262.12 mi (5,249.87 km) |
| Llanelli to Ontario (California) | 5,280.15 mi (8,497.58 km) |
| Llanelli to Ontario (Oregon) | 4,707.59 mi (7,576.13 km) |
| Llanelli to Opa-locka (Florida) | 4,251.00 mi (6,841.32 km) |
| Llanelli to Opelika (Alabama) | 4,131.16 mi (6,648.46 km) |
| Llanelli to Opelousas (Louisiana) | 4,511.60 mi (7,260.72 km) |
| Llanelli to Orange (California) | 5,300.57 mi (8,530.44 km) |
| Llanelli to Orange (Texas) | 4,600.01 mi (7,403.00 km) |
| Llanelli to Orange City (Florida) | 4,143.28 mi (6,667.97 km) |
| Llanelli to Orangeburg (South Carolina) | 3,904.04 mi (6,282.94 km) |
