Aluminium selenide is the inorganic compound with the formula Al<sub>2</sub>Se<sub>3</sub>.
It is a solid prepared by igniting a mixture of the elements at :
The pure compound is white, but typical samples are coloured. Samples are usually protected from moisture, because they hydrolyze readily, giving off highly toxic hydrogen selenide gas:
Al<sub>2</sub>Se<sub>3</sub> has been used as a precursor to hydrogen selenide, which is released when the solid is treated with acids.