| Llantrisant to Joliet (Illinois) | 3,858.32 mi (6,209.37 km) |
| Llantrisant to Jonesboro (Arkansas) | 4,227.33 mi (6,803.24 km) |
| Llantrisant to Joplin (Missouri) | 4,315.75 mi (6,945.52 km) |
| Llantrisant to Joppatowne (Maryland) | 3,479.91 mi (5,600.38 km) |
| Llantrisant to Juana Díaz (Puerto Rico) | 4,100.03 mi (6,598.36 km) |
| Llantrisant to Junction City (Kansas) | 4,309.17 mi (6,934.94 km) |
| Llantrisant to Juneau (Alaska) | 4,349.55 mi (6,999.92 km) |
| Llantrisant to Jupiter (Florida) | 4,228.54 mi (6,805.18 km) |
| Llantrisant to Jupiter Farms (Florida) | 4,232.95 mi (6,812.27 km) |
| Llantrisant to Jurupa Valley (California) | 5,310.26 mi (8,546.03 km) |
| Llantrisant to Justice (Illinois) | 3,835.56 mi (6,172.74 km) |
| Llantrisant to Kahului (Hawaii) | 7,174.59 mi (11,546.39 km) |
| Llantrisant to Kailua (Hawaii) | 7,163.48 mi (11,528.50 km) |
| Llantrisant to Kalamazoo (Michigan) | 3,724.56 mi (5,994.10 km) |
| Llantrisant to Kalispell (Montana) | 4,433.72 mi (7,135.38 km) |
