三硒化二砷是一种含砷的无机化合物，化学式As₂Se₃，为棕色固体。它和α-As₂S₃同晶。

三硒化二砷由硒和砷在500℃下直接化合，产物在220～280℃冷却得到。

Arsenic triselenide (As₂Se₃) is an inorganic chemical compound, a selenide of arsenic.

Amorphous arsenic triselenide is used as a chalcogenide glass for infrared optics, as it transmits light with wavelengths between 870 nm and 17.2 µm.

Arsenic triselenide is covalently bonded. Even so, the arsenic has a formal oxidation state of +3.