H6

H6, H06, or H-6 may refer to:

Science

 * British NVC community H6, an ecological designation
 * Sanguiin H-6, a dimeric ellagitannin found in Sanguisorba officinalis, the great burnet
 * Hydrogen-6 (H-6 or 6H), an isotope of hydrogen

Aircraft

 * Hughes OH-6 Cayuse, a 1963 American scout helicopter
 * MD Helicopters MH-6 Little Bird, a special forces variant
 * Xian H-6, a Chinese bomber
 * Besson H-6, a French flying boat
 * Sikorsky R-6, a 1943 American helicopter

Watercraft

 * HMS H6, a British submarine
 * USS H-6 (SS-149), a United States submarine
 * HMS Hurricane (H06), a British Havant-class destroyer
 * HMS Keith (H06), a British B-class destroyer

Other vehicles

 * PRR H6, a steam locomotive
 * Haval H6, a compact crossover SUV produced by Great Wall Motor
 * Hispano-Suiza H6, an automobile

Roads

 * H6 Childs Way, a road in England
 * Highway H06, a road in the Ukraine

Other uses

 * , level 6 heading markup for HTML Web pages, see HTML element
 * Flat-six engine, sometimes marketed as H6
 * Halloween: The Curse of Michael Myers, the sixth film in the Halloween franchise
 * H6: Diary of a Serial Killer, a movie
 * Composition H6, an explosive
 * H6, a watch possibly made by John Harrison