Calcium nitrate is an inorganic compound with the formula Ca(NO3)2. This colourless salt absorbs moisture from the air and is commonly found as a tetrahydrate. It is mainly used as a component in fertilizers but has other applications.

Calcium nitrate is used in agriculture to control certain plant diseases, in waste water treatment to prevent odour emission, in concrete to accelerate admixtures, in latex production and in cold packs.