The reaction between decavanadate clusters and organic cations has attracted intensive research interest due to the interesting properties of the resulting materials. The asymmetric unit of their structure consists of a complete dihydrogen decavanadate anion ([H2V10O28]−4), four organic 1-vinyl-1H-imidazol-3-ium cations (4[C5H7N2]+1), and four water molecules. The stability of the crystal arises from O–H⋯O, N–H⋯O and C–H⋯O bonding, with structural stabilization largely attributed to water molecules. Crystals have been grown by slow evaporation of the solution at room temperature. The compound has been chemically and spectroscopically characterized by a combination of elemental and thermal analyses, together with IR spectroscopy, and its structure was elucidated by X-ray diffraction. Density functional theory calculations combined with Hirshfeld surface, QTAIM, NCI, NBO, and frontier molecular orbital analyses reveal that the electronic structure of the hybrid system is governed by organic-to-inorganic charge transfer, with the organic moiety acting as an electron donor and the polyoxodecavanadate cluster serving as an electron acceptor. The combined experimental and theoretical results provide a coherent description of the bonding, noncovalent interactions, and electronic properties of the title compound.