HH9

HH9, HH-9, HH 9, HH.9, may refer to:


 * Ashes of Victory (novel), abbreviated "HH9", ninth main-line novel in the Honor Harrington novel series, part of the Honorverse fictional milieu created by David Weber
 * HH9 (album), an album by Henrik Nordvargr Björkk; see Nordvargr discography


 * HH9, one of the Hamburger–Hamilton stages in chick development
 * HH9, one of the hammerhead ribozymes
 * Nasal embryonic LHRH factor (HH9)
 * GERMAN TRAWLER V 206 Otto Bröhan (pennant: ), a WWII-era German fishing boat