Pyrophosphoryl chloride is the inorganic compound with the formula (POCl2)2O.

In terms of its chemical structure, the compound consists of two tetrahedral phosphorus sites that share an oxo bridge.

The name implies that the compound is a derivative of pyrophosphoric acid, (PO(OH)2)2O.

The compound is obtained by treating phosphoryl chloride with half an equivalent of methanol, as described in the following chemical equation:[1] Pyrophosphoryl chloride is proposed as an intermediate in the chlorination of alcohols by phosphoryl chloride.

It is also a reagent for Vilsmeier-Haack formylations.