JX may mean:
- Jx or jx, is a digraph in the Esperanto x-system orthography, representing the consonant sound, normally spelled as Ĵ or ĵ in the Esperanto alphabet
- Roland JX-3P, a MIDI capable synthesizer keyboard which debuted in 1983
- JX (artist), an early alias of DJ Jake Williams, who is more recently known as Rex the Dog
- JX (operating system), a Java operating system
- J. X. Williams, a pseudonym used by several different authors during the 1960s for many adult novels
- IBM JX, a personal computer that based on IBM PCjr, released in Japan, in 1984
- Informally for Jesus Christ