J84 may refer to:
Vehicular , a British Royal Navy WW2 Halcyon-class minesweeper Renault Scénic (model code ), a compact MPV LNER Class J84, a British locomotive class designed by Thomas Wheatley
Other uses Snub disphenoid (Johnson solid ) South Observatory (obsevatory code ), Clanfield, UK; see List of observatory codes
See also
Shenyang J-8 IV "Finback", a Chinese jet fighter plane, a variant of the MiG-21
84 (disambiguation) J (disambiguation)