Jar or JAR may also refer to:
* Jar (unit), an obsolete unit of capacitance once used by the Royal Navy
* JAR (file format), Java ARchive file
* JAR (software), for data compression
* Joint Aviation Requirements issued by Europe's Joint Aviation Authorities
Jar or JAR may also refer to:
* Jar (unit), an obsolete unit of capacitance once used by the Royal Navy
* JAR (file format), Java ARchive file
* JAR (software), for data compression
* Joint Aviation Requirements issued by Europe's Joint Aviation Authorities