Tetrabutylammonium tribromide, abbreviated to TBATB, is a pale orange solid with the formula [N(C<sub>4</sub>H<sub>9</sub>)<sub>4</sub>]Br<sub>3</sub>. It is a salt of the lipophilic tetrabutylammonium cation and the linear tribromide anion. The salt is sometimes used as a reagent used in organic synthesis as a conveniently weighable, solid source of bromine.
The compound is prepared by treatment of solid tetra-n-butylammonium bromide with bromine vapor:
Instead of bromine, tetra-n-butylammonium bromide can also be reacted with vanadium pentoxide and aqueous hydrogen peroxide, or alternatively with ceric ammonium nitrate.