This study investigates the adsorption of chromium (Cr(III)) from aqueous solutions using Algerian kaolinite clay. The structural and textural properties of the kaolinite clay were characterized using various analytical techniques, including XRD, FTIR, SEM-EDS, XPS, laser granulometry, N₂ adsorption isotherm, and TGA-DTA. The adsorption equilibrium was reached within five minutes, achieving a maximum removal rate of 99% at pH 5. The Langmuir isotherm model accurately described the adsorption process, yielding a maximum adsorption capacity of 8.422 mg/g for Cr(III). Thermodynamic parameters indicated that the adsorption process is spontaneous and endothermic, with an activation energy of 26.665 kJ/mol, suggesting the importance of diffusion in the sorption process. Advanced DFT computations, including COSMO-RS, molecular orbitals, IGM, RDG, and QTAIM analyses, revealed strong binding interactions between Cr(III) ions and the kaolinite surface. The integration of experimental and computational data enhances the understanding of Cr(III) removal using kaolinite and demonstrates its effectiveness as an adsorbent for wastewater treatment. The study highlights the synergistic application of empirical research and computational modeling in elucidating complex adsorption processes.This study investigates the adsorption of chromium (Cr(III)) from aqueous solutions using Algerian kaolinite clay. The structural and textural properties of the kaolinite clay were characterized using various analytical techniques, including XRD, FTIR, SEM-EDS, XPS, laser granulometry, N₂ adsorption isotherm, and TGA-DTA. The adsorption equilibrium was reached within five minutes, achieving a maximum removal rate of 99% at pH 5. The Langmuir isotherm model accurately described the adsorption process, yielding a maximum adsorption capacity of 8.422 mg/g for Cr(III). Thermodynamic parameters indicated that the adsorption process is spontaneous and endothermic, with an activation energy of 26.665 kJ/mol, suggesting the importance of diffusion in the sorption process. Advanced DFT computations, including COSMO-RS, molecular orbitals, IGM, RDG, and QTAIM analyses, revealed strong binding interactions between Cr(III) ions and the kaolinite surface. The integration of experimental and computational data enhances the understanding of Cr(III) removal using kaolinite and demonstrates its effectiveness as an adsorbent for wastewater treatment. The study highlights the synergistic application of empirical research and computational modeling in elucidating complex adsorption processes.