HH4, HH-4, HH 4, HH.4, may refer to:
- Field of Dishonor (novel), abbreviated "HH4", fourth main-line novel in the Honor Harrington novel series, part of the Honorverse fictional milieu created by David Weber
- HH4, a model in the series of Honda Acty trucks
- 01444 — Haywards Heath (HH4), West Sussex, England, UK; see List of dialling codes in the United Kingdom
- HH4, one of the Hamburger–Hamilton stages in chick development