Schiff bases are versatile compounds for the design of the ternary complex. An experiment has been made to synthesize two novel complexes of Co(II). Here, The primary ligand, L1 was prepared by the condensation reaction of o-toluidine with 3-formyl chromone or o-toluidine with 3- methylquinolinecarbaldehyde and the secondary ligand which was 8-Hydroxyquinoline. These potent complexes were prepared by condensation of primary and secondary ligands with Cobalt salt. The reaction was performed through the conventional reflux method. The newly synthesized chromone and quinoline derived novel compounds are proposed to have significant antimicrobial activity against selective strains of bacteria and fungi. This can be great opportunity for researchers and the use of biological applications of the synthesized novel compounds can be a part of unique field of research for the future to be focus. Chromone derivative has great biological diversity in the medicinal and pharmaceutical fields. Along with these compounds, quinoline derivatives also have antibacterial, and antifungal activities. The synthesized ligand and complex were characterized by elemental analysis, molecular weight determination, magnetic moment measurement, melting point determination, spectral analysis (IR, UV–Vis, 1H NMR, Mass, etc.), and X-ray diffraction. The synthesized complexes were paramagnetic and non-electrolytic in nature. The Uv–Vis, FTIR, NMR, and Mass spectra suggest the octahedral geometry of the complexes. The synthesized compounds were further evaluated for biological studies against selected bacterial and fungal strains. It has been observed that the antimicrobial activity of most of the complexes are better than that of ligands.