In this investigation, the corrosion inhibition properties of an N-heteroaromatic containing compound 2-(4Methoxy-phenyl)-5-naphthalen-2-yl-[1,3,4]oxadiazole (MPNO), against mild steel (MS) in 1 M HCl using various analytical techniques have been examined. This study included weight-loss measurements at different temperatures (303-323 K), electrochemical analyses using Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP), and surface morphology investigations with Scanning Electron Microscopy (SEM). The experimental results demonstrated that MPNO exhibited excellent corrosion inhibition efficiency of 85.53% at a minimal 400 ppm inhibitor concentration with a mixed-type inhibition mechanism, as evidenced by the charge transfer resistance (RCT) value of 327.02 ohm. cm(2) derived from the EIS analysis. Additionally, the analysis of quantum chemical descriptors revealed E HOMO (-8.6335 eV), E-LUMO (-1.0277 eV), energy gap (Delta E = 7.60 eV), dipole moment (mu = 2.618 D), indicating inhibitor capability to acquire electrons and donate them to the metal's vacant d-orbitals, thus enhancing its adsorption activity and inhibitory properties. The density functional theory (DFT) computational studies complemented the experimental findings and provided a deeper understanding of the interaction modes between the inhibitors and the MS surface.