Oxadiazoles, a class of nitrogen-containing heterocycles, exhibit diverse applications in pharmaceuticals, industry, and other fields. This study employs Density Functional Theory (DFT) to investigate the structural, electronic, and spectroscopic properties of four oxadiazole isomers. The B3LYP functional and the 6-311G(d,p) basis set were used for calculations. Frontier orbital energies, energy gap, chemical reactivity descriptors, dipole moment, and thermodynamic properties were computed. Additionally, IR and UV spectra were analyzed. The results indicate significant variations in electronic and thermodynamic properties among the isomers. Isomer 4 demonstrated the highest stability and electrophilicity. The calculated IR and UV spectra were compared with available experimental and theoretical data. The study provides valuable insights into the structural and reactivity trends within the oxadiazole family, contributing to a deeper understanding of their potential applications.