Silicon tetrachloride is the inorganic compound with the formula SiCl₄. It is a colourless volatile liquid that fumes in air. It is used to produce high purity silicon and silica for commercial applications.

Silicon tetrachloride is prepared by the chlorination of various silicon compounds such as ferrosilicon, silicon carbide, or mixtures of silicon dioxide and carbon. The ferrosilicon route is most common.

In the laboratory, SiCl₄ can be prepared by treating silicon with chlorine:

It was first prepared by Jöns Jakob Berzelius in 1823.

Brine can be contaminated with silica when the production of chlorine is a byproduct of a metal refining process from metal chloride ore. In rare occurrences, the silicon dioxide in silica is converted to silicon tetrachloride when the contaminted brine is electrolyzed.

Like other chlorosilanes, silicon tetrachloride reacts readily with water:

In contrast, carbon tetrachloride does not hydrolyze readily. The differing rates of hydrolysis are attributed to the greater atomic radius of the silicon atom allowing attack at silicon, and to the polar nature of the Si-Cl bonds favoring nucleophilic attack. The reaction can be noticed on exposure of the liquid to air, the vapour produces fumes as it reacts with moisture to give a cloud-like aerosol of hydrochloric acid. With methanol and ethanol it reacts to give tetramethyl orthosilicate and tetraethyl orthosilicate:

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