Glyoxal-bis(mesitylimine) is an organic compound with the formula H<sub>2</sub>C<sub>2</sub>(NC<sub>6</sub>H<sub>2</sub>Me<sub>3</sub>)<sub>2</sub> (Me = methyl). It is a yellow solid that is soluble in organic solvents. It is classified as a diimine ligand. It is used in coordination chemistry and homogeneous catalysis. It is synthesized by condensation of 2,4,6-trimethylaniline and glyoxal. In addition to its direct use as a ligand, it is a precursor to imidazole precursors to the popular NHC ligand called IMes.