Bisulfide (or bisulphide in British English) is an inorganic anion with the chemical formula HS− (also written as SH−).

Ammonium hydrosulfide, a component of "stink bombs" has not been isolated as a pure solid.

For example, the hydrated form of sodium sulfide, nominally with the formula Na2S · 9 H2O, is better described as NaSH · NaOH · 8 H2O.

A solution containing spectator-only counter ions, has a basic pH according to the following acid-base reaction: Upon treatment with an acid, bisulfide converts to hydrogen sulfide.

[6] Bisulfide salts are corrosive, strongly alkaline and release toxic hydrogen sulfide upon acidification.