Herein, we investigate the effects of CaCO3 coating on TiO2 photoanode electrodes for dye-sensitized solar cells (DSCs). TiO2 films are coated with varying thicknesses of CaCO3 using a spin-coating technique, and the resulting photoanodes are characterized for their structural, optical, and electrochemical properties. Field-emission scanning electron microscopy (FESEM) images reveal that the CaCO3 coating formed uniform nanocube structures, enhancing the surface morphology and scattering properties of the photoanode. X-ray diffraction (XRD) analysis confirms the presence of both anatase-TiO2 and calcite-CaCO3 phases, while optical measurements indicate a slight increase in the bandgap of the CaCO3-coated TiO2 films. Photovoltaic testing demonstrates that the optimal CaCO3 thickness (around 570 nm) significantly improved the power conversion efficiency (PCE) of DSSCs, achieving a maximum efficiency of 9.19 %, compared to 7.58 % for pristine TiO2. Electrochemical impedance spectroscopy (EIS) and open-circuit voltage decay (OCVD) measurements reveal that the CaCO3 coating reduced charge recombination, enhanced electron injection, and improved charge transport in the devices. Our results indicate that a thin CaCO3 layer effectively enhances the photovoltaic performance of TiO2based DSCs by reducing electron recombination, improving dye adsorption, and enhancing electron injection, while thicker coatings can negatively affect device performance due to increased recombination and electron transport barriers. These findings provide valuable insights into the design of photoanodes for efficient DSCs, emphasizing the importance of optimizing the CaCO3 coating thickness.