Ion implantation emerges as a cutting-edge method for defect engineering in crystalline materials, offering unparalleled precision in modulating thermal conductivity. In this study, we employ argon (Ar) ion implantation to manipulate the thermal and phonon transport properties of the thermoelectric material antimony telluride (Sb2Te3). By systematically varying ion implantation doses and energies, we achieve controlled defect structures, characterized comprehensively using advanced techniques such as Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). The results reveal that defect-induced structural changes, including point defects, dislocations, and amorphous-like regions, significantly suppress thermal conductivity, laying the foundation for enhanced thermoelectric efficiency. This work establishes Ar ion implantation as a scalable, tunable, and transformative approach to defect engineering, unlocking new horizons for thermoelectric materials in energy conversion and advanced thermal management applications.