Tetraethylammonium iodide is a quaternary ammonium compound with the chemical formula C8H20N+I−.

It has been used as the source of tetraethylammonium ions in pharmacological and physiological studies, but is also used in organic chemical synthesis.

[2] The crystal structure of tetraethylammonium iodide has been determined.

[3] The crystal structure is a distorted wurtzite lattice.

At the nitrogen atom, the coordination is a flattened tetrahedron.