Calcium chloride, CaCl₂, is a salt of calcium and chlorine. It behaves as a typical ionic halide, and is solid at room temperature. Common applications include brine for refrigeration plants, ice and dust control on roads, and desiccation. Because of its hygroscopic nature, anhydrous calcium chloride must be kept in tightly-sealed air-tight containers.

Calcium chloride can serve as a source of calcium ions in a solution as calcium chloride is soluble. This property can be useful for displacing ions from solution. For example, phosphate is displaced from solution by calcium