| J Mascis | J Mascis |
| J sharp | J Sharp |
| J-Curve | J curve |
| J-Pop | J-pop |
| J.D. Salinger | J. D. Salinger |
| Jaan Kirsipuu | Jaan Kirsipuu |
| Jaan Kross | Jaan Kross |
| Jaap de Hoop Scheffer | Jaap de Hoop Scheffer |
| Jaap Stam | Jaap Stam |
| Jabal Uweinat | Jebel Uweinat |
| Jabba the Hutt | Jabba the Hutt |
| Jabber | Extensible Messaging and Presence Protocol |
| Jaberg | Jaberg |
| Jabing | Jabing |
| Jablanica | Jablanica District |
| Jableh | Jableh |
| Jabloko | Yabloko |
| jabot | jabot |
| Jaca | Jaca |
| Jacana jacana | Wattled Jacana |
| Jacen Solo | List of minor Star Wars characters |
| Jachenau | Jachenau |
| Jacint Verdaguer | Jacint Verdaguer |
| Jacinto Benavente | Jacinto Benavente |
| Jack Aubrey | Jack Aubrey |
| Jack Black | Jack Black |
| Jack Brabham | Jack Brabham |
| Jack Bradbury | Jack Bradbury |
| Jack Bruce | Jack Bruce |
| Jack Butler Yeats | Jack Butler Yeats |
| Jack Cade | Jack Cade |
| Jack Coleman | Jack Coleman |
| Jack Dempsey | Jack Dempsey |
| Jack e la pianta di fagioli | Jack and the Beanstalk |
| Jack Finney | Jack Finney |
| Jack il saltatore | Spring Heeled Jack |
| Jack Johnson | Jack Johnson |
| Jack Kerouac | Jack Kerouac |
| Jack Kirby | Jack Kirby |
| Jack Lang | Jack Lang |
| Jack Lemmon | Jack Lemmon |
| Jack lo squartatore | Jack the Ripper |
| Jack London | Jack London |
| Jack Lynch | Jack Lynch |
| Jack Nance | Jack Nance |
| Jack Nicholson | Jack Nicholson |
| Jack Palance | Jack Palance |
| jack rabbit | jackrabbit |
| Jack RadCliffe | Jack Radcliffe |
| Jack Ruby | Jack Ruby |
| Jack Russell Terrier | Jack Russell Terrier |
| Jack Shephard | Jack Shephard |
| Jack Skeletron | Jack Skellington |
| Jack Sparrow | Captain Jack Sparrow |
| Jack Steinberger | Jack Steinberger |
| Jack Straw | Jack Straw |
| Jack Swigert | Jack Swigert |
| Jack Vance | Jack Vance |
| Jack Williamson | Jack Williamson |
