Calcium fluoride is the inorganic compound of the elements calcium and fluorine with the formula CaF₂. It is a white insoluble solid. It occurs as the mineral fluorite (also called fluorspar), which is often deeply coloured owing to impurities.

The compound crystallizes in a cubic motif called a fluorite structure.

Ca²⁺ centres are eight-coordinate, being centered in a "box" for eight F⁻ centres. Each F⁻ centre is coordinated to four Ca²⁺ centres. Although perfectly packed crystalline samples are colorless, the mineral is often deeply colored due to the presence of F-centers. The same crystal structure is found in numerous ionic compounds with formula AB₂, such as CeO₂, cubic ZrO₂, UO₂, ThO₂ and PuO₂. A related structure is the antifluorite structure, where the anions and cations are swapped, such as Be₂C.

The mineral fluorite is abundant, widespread, and mainly of interest as a precursor to HF. Thus, little motivation exists for the industrial production of CaF₂. High purity CaF₂ is produced by treating calcium carbonate with hydrofluoric acid:

Naturally occurring CaF₂ is the principal source of hydrogen fluoride, a commodity chemical used to produce a wide range of materials. Calcium fluoride in the fluorite state is of significant commercial importance as a fluoride source. Hydrogen fluoride is liberated from the mineral by the action of concentrated sulfuric acid:

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