A polyoxometalate-based hybrid is produced by the copolymerization of a terminal-unsaturated surfactant-encapsulated polyoxometalate and methyl methacrylate. This hybrid exhibits flexible processability, high transparency of the polymer, and high fluorescence of the inorganic cluster (see Figure). The method presented in this paper provides general access to the fabrication of organic-inorganic electrostatic-complex-based materials in polymer matrices.