Abstract: In this study, amorphous copper stannate (a-CuSnO₃) was synthesized via a co-precipitation method followed by annealing, and its photoelectrochemical performance for water splitting under visible light irradiation was investigated. The structure, morphology, and optical properties of the samples were characterized using XRD, FE-SEM, UV–vis, LSV, and light stability analyses. The results revealed that the a-CuSnO₃ sample exhibited a spherical morphology, and its direct band gap was determined to be approximately 2.34 eV. Photoelectrochemical measurements in a three-electrode cell indicated that the a-CuSnO₃ photoanode deposited on an FTO substrate generated a photocurrent density of 0.17 mA/cm², which was significantly higher than that of the ITO-based counterpart. Moreover, the electrode retained its stability after 180 minutes of continuous illumination. These results demonstrate that the synthesized a-CuSnO₃ can serve as an efficient and stable photoanode for photoelectrochemical cells aimed at sustainable hydrogen production.