Polonium tetrachloride (also known as polonium(IV) chloride) is a chemical compound with the formula PoCl₄. The salt is a hygroscopic bright yellow crystalline solid at room temperature. Above 200 °C, it tends to decompose into polonium dichloride and excess chlorine, similar to selenium tetrachloride and tellurium tetrachloride.^[1]

Polonium tetrachloride is either monoclinic or triclinic.

Polonium tetrachloride is bright yellow at room temperature. At its melting point (300 °C), it becomes straw yellow, and at its boiling point (390 °C), it becomes scarlet. Its vapours are purple-brown until 500 °C, when they turn blue-green.^[1]

Polonium tetrachloride may be prepared by:

• halogenation of polonium dioxide with dry hydrogen chloride, gaseous thionyl chloride, or phosphorus pentachloride;^[1]
• dissolving of polonium metal in hydrochloric acid;
• heating polonium dioxide to 200 °C in carbon tetrachloride vapour;
• reaction of polonium metal with dry chlorine gas in 200 °C.

Polonium tetrachloride forms a complex with two moles of tributyl phosphate.

Like selenium tetrachloride and tellurium tetrachloride, polonium tetrachloride forms PoCl⁻
₅ and PoCl²⁻
₆ halogen complexes.^[1]