Barium Chloride is the ionic chemical compound with the formula BaCl2. It is one of the most important water-soluble salts of barium. Like other barium salts, it is toxic and imparts a yellow-green coloration to a flame. It is also hygroscopic.

As a cheap, soluble salt of barium, Barium Chloride finds wide application in the laboratory. It is commonly used as a test for sulfate ion. In industry, It is mainly used in the purification of brine solution in caustic chlorine plants and also in the manufacture of heat treatment salts, case hardening of steel, in the manufacture of pigments, and in the manufacture of other barium salts. BaCl2 is also used in fireworks to give a bright green color. However, its toxicity limits its applicability. Barium Chloride is also used (with Hydrochloric acid) as a test for sulfates. When these two chemicals are mixed with a sulfate salt, a white precipitate forms, which is barium sulfate.

Barium Chloride, along with other water-soluble barium salts, is highly toxic. Sodium sulfate and magnesium sulfate are potential antidotes because they form the insoluble solid barium sulfate BaSO4, which is much less toxic.