| Abbreviation | Definition |
|---|---|
| JOM | Johnson-O'Malley Act of 1934 |
| JoSSA | Joint Seat Allocation Authority |
| JPA | Joint Powers Authority |
| JPDO | Joint Planning and Development Office |
| JPRS | Joint Publications Research Service |
| JSM | Jock Strap Medal |
| JTC | Jakarta Tomcat Connectors |
| JTPA | Job Training Partnership Act |
| JVA | Jackson-Vanik Amendment |
| JVC | Just Very Consistent |
| JVU | Justice and Victims Unit |
| K | Contract |
| KAGA | Keep America Great Always |
| KAPL | Knolls Atomic Power Laboratory |
| KATM | Katmai National Park and Preserve |
| KB | Knowles Building |
| KC | Khmer Communists |
| KCA | Kill Corrupt Authority |
| KCFB | Kansas City Federal Building |
| KGB | Komitet Gosudarstvennoi Bezopasnosti |