Abstarct: In recent years, the use of novel materials for the removal of environmental pollutants, especially industrial dyes, has become a significant approach in materials science and environmental engineering. mextal-Organic frxameworks (MOFs) have attracted considerable attention as efficient adsorbents for pollutant removal due to their unique properties such as high surface area, tunable chemical functionality, and suitable stability. In this study, the UiO-66-OH/CuO composite was synthesized with the aim of enhancing the adsorption performance of Toluidine Blue dye. First, the mextal-organic frxamework UiO-66-OH was synthesized via a solvothermal method and then combined with copper oxide (CuO) nanoparticles. Analytical techniques including FTIR, XRD, SEM, EDX, and TGA were carried out to confirm the successful formation of the composite and to evaluate its structural, thermal, and elemental characteristics. The results indicated that the crystalline and chemical structures of the individual components were preserved in the composite, with a uniform distribution of CuO within the UiO-66-OH matrix. The adsorption capacity of Toluidine Blue dye was evaluated using UV-Vis spectroscopy. The results revealed that the UiO-66-OH/CuO composite exhibited a high adsorption capacity of approximately 118.75 mg/g within 90 minutes. Moreover, the reusability of the adsorbent was assessed, and it was found that about 88% of the initial adsorption capacity was retained even after five adsorption-desorption cycles. Adsorption kinetics studies demonstrated that the data fit well with the pseudo-second-order kinetic model, indicating the dominance of chemical interactions in the adsorption process. A reasonable fit with the Langmuir isotherm model suggested the presence of adsorption sites with different energies on the surface of the adsorbent. Overall, the UiO-66-OH/CuO composite, due to its high adsorption capacity, short adsorption time, and reusability, is proposed as an efficient and cost-effective adsorbent for the removal of TB dye from aqueous environments.