<p>A new series of homo- and heteroleptic Zn(II) and Cd(II) complexes has been synthesized using proline and N-donor ligands and characterized using FT-IR, NMR, and TGA/DSC techniques. In FT-IR spectra, the disappearance of the broad OH band and the appearance of new vibrational bands for Zn–O, Zn–N, Cd–O, and Cd–N indicate the formation of complexes. In ¹³C-NMR and ¹H-NMR spectra, the downfield shift in C = O, sharpness in the N–H peak, and additional peaks of hetero-ligands also validate the complex formation. Additionally, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) provided insights into the complexes’ thermal stability and decomposition behavior. The main objective of this work was to explore the influence of amino acid–based coordination on the structural, electronic, and biological properties of Zn(II) and Cd(II) complexes. The novelty of this study lies in the use of proline as a biocompatible ligand framework, combined with diverse N-donor co-ligands, to achieve tunable DNA-binding affinity and antioxidant activity. UV–Visible spectroscopy and cyclic voltammetry confirmed significant intercalative binding interactions with DNA, while docking and antioxidant assays revealed promising bioactive potential. The results suggest potential applications of these complexes in medicinal and bioinorganic chemistry.</p>