The barium titanate Ba1-xCe2x/3TiO3 (BCTx, x = 0, 1, 2 and 3 %) have been produced using the sol-gel process. The impact of cerium concentration on structure and optical properties was examined using techniques such as X-ray diffraction, infrared spectroscopy, Raman spectroscopy and UV–visible spectroscopy. DFT calculation were carried out on BCTx to obtain an extensive comprehension of the relationship between the structure and electronic properties of BCTx. The findings demonstrate a tetragonal structure for BCT0 and a pseudo-cubic for the doped samples. The UV–visible study indicates a successive reduction in bandgap due to vacancies in the A site, lattice defect formation and local bond distortion. For every sample, the electronic band structure showed a direct band gap. The partial density of states (PDOS) revealed that the valence band was dominated by the 2p orbitals of the O atoms. However, the conduction band was formed by the 3d orbitals of the Ti atom.