| JA | Judge advocate |
| JACCE | Joint air component coordination element |
| JAGIC | Joint air-ground integration center |
| JAOC | Joint air operations center |
| JAOP | Joint air operations plan |
| JCET | Joint combined exchange training |
| JCMEC | Joint captured materiel exploitation center |
| JCSB | Joint contracting support board |
| JDDC | Joint doctrine development community |
| JDDE | Joint deployment and distribution enterprise |
| JDDOC | Joint deployment and distribution operations center |
| JDEC | Joint document exploitation center |
| JDISS | Joint deployable intelligence support system |
| JDN | Joint doctrine note |
| JDNO | Joint data network operations officer |
| JDPC | Joint Doctrine Planning Conference |
| JDPI | Joint desired point of impact |
| JEMSO | Joint electromagnetic spectrum operations |
| JEZ | Joint engagement zone |
| JFACC | Joint force air component commander |
| JFC | Joint force commander |
| JFE | Joint fires element |
| JFLCC | Joint force land component commander |
| JFMCC | Joint force maritime component commander |
| JFO | Joint fires observer |
| JFS | Joint force surgeon |
| JFSOCC | Joint force special operations component commander |
| JFUB | Joint facilities utilization board |
| JIA | Joint individual augmentee |
| JIACG | Joint interagency coordination group |
| JICO | Joint interface control officer |
| JIDC | Joint interrogation and debriefing center |
| JIOC | Joint intelligence operations center |
| JIPOE | Joint intelligence preparation of the operational environment |
| JIPTL | Joint integrated prioritized target list |
| JISE | Joint intelligence support element |
| JLEnt | Joint logistics enterprise |
| JLOC | Joint logistics operations center |
| JMAO | Joint mortuary affairs office |
| JMET | Joint mission-essential task |
| JMP | Joint manpower program |
| JNCC | Joint network operations control center |
| JOA | Joint operations area |
| JOC | Joint operations center |
| JP | Joint publication |
| JPEC | Joint planning and execution community |
| JPG | Joint planning group |
| JPP | Joint planning process |
| JPPC | Joint personnel processing center |
| JPRC | Joint personnel recovery center |
| JRCC | Joint reception coordination center |
| JRFL | Joint restricted frequency list |
| JRRB | Joint requirements review board |
| JRSOI | Joint reception, staging, onward movement, and integration |
| JS | Joint staff |
| JSA | Joint security area |
| JSC | Joint security coordinator |
| JSCC | Joint security coordination center |
| JSDS | Joint Staff doctrine sponsor |
| JSOA | Joint special operations area |
| JSOTF | Joint special operations task force |
| JSPS | Joint Strategic Planning System |
| JTAC | Joint terminal attack controller |
| JTB | Joint Transportation Board |
| JTC | Joint targeting cycle |
| JTCB | Joint targeting coordination board |
| JTD | Joint table of distribution |
| JTF | Joint task force |
| JTF-CS | Joint Task Force-Civil Support |
| JTL | Joint target list |
| JUOs | Joint urban operations |
| JWICS | Joint Worldwide Intelligence Communications System |