Solar water splitting is an alternative method to produce H2 using sunlight and specialized semiconductors. Many semiconductor oxides have been used as photocatalysts in these reactions, and strategies have been developed to improve the efficiency of the catalytic process. Ionic doping in semiconductors is considered efficient strategy to enhance the charge transport and avoiding its rapid recombination. This study, a simple polymeric precursor method was employed for the fabrication of pristine copper tungstate (CuWO4) film and that of varying doping concentration (1%, 3%, and 5%) of lithium (Li:CuWO4) and magnesium (Mg:CuWO4). Films were prepared from copper-tungsten citrate resin and thermal treated at 500°C/2h. The chemical composition, valence state, optical, morphological and structural properties of the synthesized materials were characterized using X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), field emission–scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), respectively. Spherical shaped nanostructures were observed, just like confirmed triclinic structure and the presence of dopants with elongation of crystalline lattice. DRS spectra confirmed the chemical composition of films and greater evidence of the Mg dopant. The impurities occupied interstitial sites in the host CuWO4 lattice and induced shift for lower optical band gap energy. The presence of dopants was clearly observed with photoelectrochemical response, modifying n-type behavior of host film for p-type in the doped CuWO4 films. Pristine CuWO4 electrodes reached higher anodic photocurrent density of 20 mA cm-2 at 1.0 V vs. Ag/AgCl (0.1 mol L-1 Na2SO4), while Li:CuWO4 and Mg:CuWO4 electrodes obtained higher cathodic photocurrent density of 123 and 78 mA cm-2 at -0.4 V vs. Ag/AgCl (0.1 mol L-1 Na2SO4), respectively. Doping with Li or Mg in host CuWO4 electrodes favored the inhibition of the charge recombination and efficient applied bias photon-to-current efficiency for hydrogen evolution reaction. Moreover, density functional theory (DFT) calculations were carried out to model structures and to understand theoretically the alterations of the doped CuWO4 structures experimentally obtained, besides electronic properties from the analysis of density of states (DOS) and projected density of states (PDOS). Therefore, CuWO4 films are promising for potential application in water splitting and photocatalytic process.