Cobalt(II) chloride is an inorganic compound of cobalt and chlorine, with the formula CoCl
₂. It is a sky blue crystalline solid.
The compound forms several hydrates CoCl
₂O, for n = 1, 2, 6, and 9. Claims of the formation of tri- and tetrahydrates have not been confirmed. The dihydrate is purple and hexahydrate is pink. It is usually supplied as the hexahydrate CoCl
₂O, which is one of the most commonly used cobalt compounds in the lab.