A novel Schiff base ligand derived from o-Vanillin, N, N-Diethyl-p-phenylenediamine in 1:1 molar ratio, and its metal complexes of Mn (II), Co (II), Ni (II), Cu (II), Zn (II) and Zr (IV) were synthesized by microwave and conventional methods. The ligand and its complexes were characterized by elemental analysis, FT-IR, UV-Vis, 1HNMR, mass spectroscopy as well as Thermo-Gravimetric Analysis (TGA). The geometry of the proposed Structures of the chelates based on their Electronic spectra, Electron paramagnetic resonance (EPR) and magnetic moment. The thermal dehydration and decomposition of the complexes were studied kinetically using the integral method applying the Coats–Redfern and Horowitz Metzger equation. Study the Variation of magnetic susceptibility at Different temperature for Mn (II) and Co (II) complexes. Surface morphologies were analyzed by Scanning electron microscopy (SEM). The ligand and its metal complexes were screened for antimicrobial activity against Gram-positive, Gram-negative bacteria as well as fungi. Cu (II) complex achieved a brilliant inhibition zone diameter against E. coli almost reached the inhibition zone diameter record by standard positive control Cephalothin making it eligible for treatment of E. coli. Also, Cytotoxicity Evaluation was applied against two cell lines; human colon carcinoma (HCT) and liver cancer cells (HepG-2).