This study develops a defect-engineered quasi-UiO-66 MOF adsorbent with enhanced performance for removing the organic dye Alizarin Yellow GG. Introducing structural defects and controlled thermal treatment to generate exposed metal sites significantly improved adsorption capacity, providing insights for designing advanced MOF adsorbents. This research successfully developed a controlled thermal partial ligand elimination. This process introduced structural modifications, forming additional open zirconium sites and hierarchical pores within the framework. These unique features contributed to the superior adsorption performance of the Q-UiO-66 adsorbent towards the organic dye Alizarin Yellow GG, exhibiting an unprecedented uptake capacity of 398.2 mg.g􀀀 1. Comprehensive characterization techniques, including FT-IR, FE-SEM, BET, XRD, and elemental analyses, were employed to understand the adsorbent’s properties. Furthermore, the optimization of the adsorption process was done using the Box-Behnken design approach, and the adsorption behavior was well-described by the Langmuier- Freundlich isotherm and pseudo-second-order kinetic models. The findings highlight the significant potential of this novel, defect-engineered Q-UiO-66 MOF adsorbent for effective dye removal applications