Disodium Sulfide Red or sodium sulfide is the name used to refer to the chemical compound Na2S. It is colorless water-soluble salts that give strongly alkaline solutions. When exposed to moist air, Disodium Sulfide Red and its hydrates emit hydrogen sulfide, which smells much like rotten eggs or flatus.

Disodium Sulfide Red is primarily used in pulp and paper industry. It is used in water treatment as an oxygen scavenger agent, in the photographic industry to protect developer solutions from oxidation, in textile industry as a bleaching, as a desulfurising and as a dechlorinating agent and in leather trade for the sulfitisation of tanning extracts.

It is used in chemical manufacturing as a sulfonation and sulfomethylation agent. It is used in the production of rubber chemicals, sulfur dyes and other chemical compounds. It is used in other applications including ore flotation, oil recovery, food preservative, making dyes, and detergent.

For safety issues, Disodium Sulfide Red is strongly alkaline and can cause skin burns. Acids react with it to rapidly produce hydrogen sulfide, which is a toxic and foul-smelling gas.