| London Colney to Joliet (Illinois) | 3,970.57 mi (6,390.02 km) |
| London Colney to Jonesboro (Arkansas) | 4,343.33 mi (6,989.92 km) |
| London Colney to Joplin (Missouri) | 4,427.67 mi (7,125.64 km) |
| London Colney to Joppatowne (Maryland) | 3,602.00 mi (5,796.86 km) |
| London Colney to Juana Díaz (Puerto Rico) | 4,232.33 mi (6,811.28 km) |
| London Colney to Junction City (Kansas) | 4,417.21 mi (7,108.82 km) |
| London Colney to Juneau (Alaska) | 4,395.18 mi (7,073.35 km) |
| London Colney to Jupiter (Florida) | 4,356.77 mi (7,011.54 km) |
| London Colney to Jupiter Farms (Florida) | 4,361.13 mi (7,018.56 km) |
| London Colney to Jurupa Valley (California) | 5,403.02 mi (8,695.31 km) |
| London Colney to Justice (Illinois) | 3,947.79 mi (6,353.36 km) |
| London Colney to Kahului (Hawaii) | 7,217.47 mi (11,615.40 km) |
| London Colney to Kailua (Hawaii) | 7,203.44 mi (11,592.81 km) |
| London Colney to Kalamazoo (Michigan) | 3,837.84 mi (6,176.41 km) |
| London Colney to Kalispell (Montana) | 4,514.16 mi (7,264.84 km) |
