4J or 4-J may refer to: 4J Studios, a Scottish video game developer Somon Air's IATA code Eugene School District 4J 4J Road, a section of Wyoming Highway 50 4J, the production code for the 1975 Doctor Who serial The Android Invasion
In aircraft: TA-4J, a model of Douglas A-4 Skyhawk F-4J Phantom, see McDonnell Douglas F-4 Phantom II F-4J Phantom II, see List of McDonnell Douglas F-4 Phantom II variants F-4J(UK), see McDonnell Douglas F-4 Phantom II non-U.S. operators L-4J, a model of Piper J-3
See also J4 (disambiguation)