Cadmium chloride is a white crystalline compound of cadmium and chloride, with the formula CdCl₂. This salt is a hygroscopic solid that is highly soluble in water and slightly soluble in alcohol. The crystal structure of cadmium chloride (described below), is a reference for describing other crystal structures. Also known are CdCl₂·H₂O and the hemipentahydrate CdCl₂·2.5H₂O.

Anhydrous cadmium chloride forms a layered structure consisting of octahedral Cd²⁺ centers linked with chloride ligands. Cadmium iodide, CdI₂, has a similar structure, but the iodide ions are arranged in a HCP lattice, whereas in CdCl₂ the chloride ions are arranged in a CCP lattice.

The anhydrous form absorbs moisture from the air to form various hydrates. Three of these hydrates have been examined by X-ray crystallography.

Cadmium chloride dissolves well in water and other polar solvents. It is a mild Lewis acid.

Solutions of equimolar cadmium chloride and potassium chloride give potassium cadmium trichloride. With large cations, it is possible to isolate the trigonal bipyramidal [CdCl₅]³⁻ ion.

Cadmium metal is soluble in molten cadmium chloride, produced by heating cadmium chloride above 568 °C. Upon cooling, the metal precipitates.

Anhydrous cadmium chloride can be prepared by the reaction of hydrochloric acid and cadmium metal or cadmium oxide.

The anhydrous salt can also be prepared from anhydrous cadmium acetate using hydrogen chloride or acetyl chloride.