{n-Bu4N}{Cu(toluene-3,4-dithiolato radical anion)(toluene-3,4-dithiolato)} is a significant organometallic compound with diverse applications in coordination chemistry, catalysis, and materials science. This complex features a copper center coordinated to a toluene-3,4-dithiolato radical anion and a toluene-3,4-dithiolato ligand, associated with the tetra-n-butylammonium cation.