| Llantwit Major to Joliet (Illinois) | 3,858.51 mi (6,209.68 km) |
| Llantwit Major to Jonesboro (Arkansas) | 4,226.93 mi (6,802.59 km) |
| Llantwit Major to Joplin (Missouri) | 4,315.97 mi (6,945.89 km) |
| Llantwit Major to Joppatowne (Maryland) | 3,478.44 mi (5,598.01 km) |
| Llantwit Major to Juana Díaz (Puerto Rico) | 4,094.22 mi (6,589.01 km) |
| Llantwit Major to Junction City (Kansas) | 4,309.94 mi (6,936.18 km) |
| Llantwit Major to Juneau (Alaska) | 4,356.04 mi (7,010.36 km) |
| Llantwit Major to Jupiter (Florida) | 4,225.58 mi (6,800.41 km) |
| Llantwit Major to Jupiter Farms (Florida) | 4,230.00 mi (6,807.53 km) |
| Llantwit Major to Jurupa Valley (California) | 5,312.81 mi (8,550.15 km) |
| Llantwit Major to Justice (Illinois) | 3,835.76 mi (6,173.06 km) |
| Llantwit Major to Kahului (Hawaii) | 7,181.16 mi (11,556.96 km) |
| Llantwit Major to Kailua (Hawaii) | 7,170.22 mi (11,539.36 km) |
| Llantwit Major to Kalamazoo (Michigan) | 3,724.61 mi (5,994.17 km) |
| Llantwit Major to Kalispell (Montana) | 4,437.52 mi (7,141.50 km) |
