Tetra-n-butylammonium triiodide (TBAI3) is a quaternary ammonium salt with a triiodide counterion.

It is a common carrier of the triiodide used in chemical synthesis of photovoltaic materials,[2] organic conductors and superconductors.

[3] In crystals, the triiodide moieties are linear and shows high crystallinity.

[4][5] The crystals have a black appearance with a needle or plate-like habit.