碘化铋是一种绿黑色晶体，化学式 BiI₃。

碘化铋的晶体结构特殊,晶胞中碘按六方最密堆积，铋隔一层填充于三分之二的八面体空隙,形成一种层状结构。

Bismuth(III) iodide is the inorganic compound with the formula BiI₃. This gray-black solid is the product of the reaction of bismuth and iodine, which once was of interest in qualitative inorganic analysis.

Bismuth(III) iodide adopts a distinctive crystal structure, with iodide centres occupying a hexagonally closest-packed lattice, and bismuth centres occupying either none or two-thirds of the octahedral holes (alternating by layer), therefore it is said to occupy one third of the total octahedral holes.