Titanium tetrachloride is the inorganic compound with the formula TiCl₄. It is an important intermediate in the production of titaniummetal and the pigment titanium dioxide. TiCl₄ is an unusual example of a metal halide that is highly volatile. Upon contact with humid air, it forms spectacular opaque clouds of titanium dioxide (TiO₂) and hydrogen chloride (HCl). It is sometimes referred to as "tickle" due to the phonetic resemblance of its molecular formula (TiCl₄) to the word

TiCl₄ is produced by the chloride process, which involves the reduction of titanium oxide ores, typically ilmenite (FeTiO₃) with carbonunder flowing chlorine at 900 °C. Impurities are removed by distillation.

2 FeTiO₃ + 7 Cl₂ + 6 C → 2 TiCl₄ + 2 FeCl₃ + 6 CO

The coproduction of FeCl₃ is undesirable, which has motivated the development of alternative technologies. Instead of directly using ilmenite, "rutile slag" is used. This material, an impure form of TiO₂, is derived from ilmenite by removal of iron, either using carbon reduction or extraction with sulfuric acid. Crude TiCl₄ contains a variety of other volatile halides, including vanadyl chloride (VOCl₃), silicon tetrachloride (SiCl₄), and tin tetrachloride (SnCl₄), which must be separated.