A new series of transition metal complexes of Co(II), Ni(II), Cu(II) and Zn(II) were synthesized from the Schiff base ligands: 4-(4-aminophenylsulfonyl)-N-(thiophene-2-ylmethylene)aniline (SB1) and 4-(4-aminophenyl sulfonyl)-N-(3,4-dimethoxybenzylidene) aniline (SB2). All the prepared compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility, IR, UV-visible spectroscopy, H1 NMR and C13 NMR. From the physicochemical studies and spectral data, the ligands were found to be bidentate with the general composition [M(L) 2Cl2] [Where M= Co(II), Ni(II), Co(II) and Zn(II); L = Schiff base Ligand]. The lower conductivity data confirmed the non-electrolytic nature of the complexes. The corrosion inhibition characteristics of Schiff base ligands and their metal complexes on mild steel in 0.1 M HCl solution was studied by chemical method. The adsorption of inhibitors on mild steel surface obeyed Langmuir, Frumkin and Temkin adsorption isotherm. The calculated thermodynamic parameters for adsorption reveal a strong interaction between the inhibitors and the mild steel surface. The ligands and their metal complexes were screened for their antimicrobial and found to exhibit moderate to good activity.