The present study reports the green synthesis, structural characterization, and antimicrobial evaluation of Manganese (II) complexes derived from amide-based ligands. The complexes were synthesized under eco-friendly conditions without the use of toxic solvents or harsh reagents. Infrared spectral analysis confirmed the bidentate coordination of the amide ligands through the carbonyl oxygen and pyrimidine nitrogen atoms. Electronic spectral data suggested tetrahedral geometry around the Mn (II) ion, which was further supported by magnetic moment measurements. The complexes exhibited enhanced thermal stability compared to the free ligands, indicating strong metal–ligand interactions. Antimicrobial screening against selected bacterial and fungal strains demonstrated significant biological activity, suggesting that amide-based Mn (II) complexes could serve as potential candidates for bioinorganic and pharmaceutical applications.