| Abbreviation | Definition |
|---|---|
| JJP | John J. Popovic |
| JJR | James J. Reeves |
| JJR | Jean Jacques Rousseau, philosopher |
| JJR | Joseph Jenkins Roberts (Founder of Liberia) |
| JJW | Jerry Jeff Walker |
| JK | Jackie Kennedy |
| JK | Jim King |
| JK | John Kerry |
| JKC | Jack Kent Cooke |
| JKC | Joe King Carrasco |
| JKF | Jeremy K. Fiest |
| JKN | John Kaizan Neptune |
| JKQ | Jonathan Ke Quan |
| JL | Janet Lawson |
| JL | Jason Lau |
| JL | Jennifer Lawrence |
| JL | John Laffnie |
| JL | John Lennon |
| JL | Ju Long |
| JLB | James Leonard Brierley Smith (South African ichthyologist) |