| Llantwit Major to Odessa (Texas) | 4,882.37 mi (7,857.42 km) |
| Llantwit Major to Ogden (Utah) | 4,733.75 mi (7,618.24 km) |
| Llantwit Major to Oildale (California) | 5,284.13 mi (8,503.98 km) |
| Llantwit Major to Ojus (Florida) | 4,275.78 mi (6,881.21 km) |
| Llantwit Major to Okemos (Michigan) | 3,659.57 mi (5,889.52 km) |
| Llantwit Major to Oklahoma City (Oklahoma) | 4,512.39 mi (7,261.99 km) |
| Llantwit Major to Okmulgee (Oklahoma) | 4,446.79 mi (7,156.42 km) |
| Llantwit Major to Olathe (Kansas) | 4,239.89 mi (6,823.44 km) |
| Llantwit Major to Old Jamestown (Missouri) | 4,066.49 mi (6,544.38 km) |
| Llantwit Major to Oldsmar (Florida) | 4,278.06 mi (6,884.87 km) |
| Llantwit Major to Olean (New York) | 3,448.52 mi (5,549.86 km) |
| Llantwit Major to Olive Branch (Mississippi) | 4,235.46 mi (6,816.31 km) |
| Llantwit Major to Olivehurst (California) | 5,157.59 mi (8,300.35 km) |
| Llantwit Major to Olney (Maryland) | 3,520.10 mi (5,665.05 km) |
| Llantwit Major to Olympia (Washington) | 4,746.97 mi (7,639.52 km) |
