| Acronym | Definition |
|---|
| ACJ | Administration of Criminal Justice (various locations) |
| ACJ | Allegheny County Jail (Pennsylvania) |
| ACJ | Asociación Cristiana de Jóvenes (Christian Youth Association, Guatemala) |
| ACJ | Acromioclavicular Joint |
| ACJ | A319 Corporate Jet (Airbus aircraft) |
| ACJ | Airbus Corporate Jetliner (aviation) |
| ACJ | Advisory Committee on the Judiciary (New York) |
| ACJ | American Committee on Jerusalem |
| ACJ | American Communication Journal |
| ACJ | Allied Council for Japan (est. 1945) |
| ACJ | American Council for Judaism (est. 1942) |
| ACJ | American Council on Japan |
| ACJ | Australian College of Journalism |
| ACJ | Alianza Mundial de Asociaciones Cristianas de Jóvenes (Spanish: World Alliance of YMCAs) |
| ACJ | Arthrites Chroniques Juvéniles (French: Chronic Juvenile Arthritis) |
| ACJ | Anti-Car-Jacking (car security system) |
| ACJ | Association Culture et Jeunesse (French: Culture and Youth Association) |
| ACJ | Advisory Circular Joint |
| ACJ | Artificially Constructed Junction |