The reaction of equimolar amounts of UO 2 (OAc) 2 • 2H 2 O, 2,6-diformyl-4-methylphenol, and N-(hydroxyethyl)ethylenediamine in methanol affords a dinuclear trans-uranyl(VI) complex of the molecular formula [(UO 2 ) 2 (μ-L) 2 ] (L 2− = 2-formyl-4methyl-6-((2-(2-oxidoethylamino)ethylimino)methyl)phenolate) in 65% yield. Detailed structural elucidation of the complex was performed by using single-crystal X-ray crystallographic and spectroscopic studies. In [(UO 2 ) 2 (μ-L) 2 ], the metal centers are in edge-shared pentagonal-bipyramidal N 2 O 5 coordination spheres assembled by the two meridional ONNO-donor bridging L 2− and two pairs of mutually trans oriented oxo groups. The complex is redox active and displays two successive metal-centered one-electron reductions at E pc = −0.71 and −1.03 V in N,N-dimethylformamide solution. The redox-active complex was used as a heterogeneous catalyst for electrochemical hydrogen evolution from aqueous medium at pH 7 with a turnover frequency (TOF) of 384 h −1 and a Tafel slope of 274 mV dec −1 . The Faradaic efficiency of [(UO 2 ) 2 (μ-L) 2 ] was found to be 84%. Beyond the electrocatalytic response, the [(UO 2 ) 2 (μ-L) 2 ]-TiO 2 −N719 composite also exhibited significant heterogeneous photocatalytic hydrogen evolution activity in neutral aqueous medium under visible light and provided a yield of 3439 μmol g cat −1 of H 2 in 4 h with a TOF of 172 h −1 and apparent quantum yield (AQY) of 7.6%.