This investigation presents a comprehensive analysis of transition metal complexes formed from a novel Triazole Schiff Base Ligand, (E)-2-(2-(1-(1H-benzo[d][1,2,3]triazol-1-yl)propan-2-ylidene)hydrazineyl)-2-oxoacetamide (OXO). High-yield syntheses produced Cr(III), Co(II), Cu(II), and Cd(II) complexes, characterized as non-electrolytic with 1:1 metal-ligand stoichiometry. DFT calculations using LANL2DZ basis sets, and B3LYP correlation function revealed distorted octahedral structures for Cr(III), Co(II), and Cd(II) complexes, while Cu(II) exhibited square planar geometry. Antimicrobial testing against S. aureus, B. subtilis, P. aeruginosa, E. coli, A. flavus, and C. albicans showed promising activities, with the Cd(II) complex demonstrating notable efficacy. Additionally, an assessment of the complexes' antitumor potential targeting MCF-7 (Breast carcinoma) cells revealed that the [Cd(OXO)Cl2(H2O)2] complex exhibited superior efficacy, with an IC50 value of 36.14 μg/ml, surpassing that of cisplatin. Notably, this complex demonstrated diminished cytotoxicity towards normal cells (VERO cells) compared to cisplatin. Molecular docking studies with protein structures 2JFZ (H. pylori glutamate racemase), 3QX3 (MCF cells), and 6XBH (COVID-19 virus protein) provided insights into binding modes and energy profiles. Molecular Electrostatic Potential (MEP) calculations at the DFT level complemented experimental data. The study elucidated stable electronic configurations, HOMO–LUMO energy gaps, chemical hardness, and dipole moments of the complexes. Spectroscopic findings suggested a square planar geometry for the Cu(II) complex, consistent with DFT results. This research underscores these synthesized compounds' versatile applications and promising bioactive properties, emphasizing their potential in antimicrobial, antitumor, and antiviral studies. The comprehensive characterization and biological evaluations provide a solid foundation for further developing these metal complexes as potential therapeutic agents.