J4

J4/J04, J-4/J-04 or J.4/J.04 may refer to:

== In science and academia == ATC code J04 Antimycobacterials, a subgroup of the Anatomical Therapeutic Chemical Classification System Janko group J4, in mathematics S/2003 J 4, a natural satellite of Jupiter J04 : acute laryngitis and tracheitis ICD-10 code Square cupola, Johnson Solid number 4