4D

4D or 4-D may refer to:

* The Fourth dimension (disambiguation)
*The IRIS-4D series of servers and workstations from Silicon Graphics
* Class 4-D, a classification of the Selective Service System
* 4-D, a psychedelic drug.
* 4-D film - combines 3-D film and physical effects
* Cinema 4D - a commercial cross platform 3D graphics application
* 4D (train) in Melbourne, Australia
* 4-Digits - a lottery in Malaysia and Singapore
* Air Sinai - IATA code
* 4th Dimension (Software) - a web application with database development environment