Utilizing gravimetric and electrochemical measurement techniques, the effective performance of inhibitive and adsorption properties of aqueous extract obtained from destructive distillation of palmyra palm (Borassus flabellifer Linn.) peduncle (BFP) for the corrosion of mild steel (MS) in 0.5 M H2SO4 and 1 M HCl were investigated. From the experimental results, an aqueous extract of BFP was found to be a good adsorption inhibitor for the corrosion of MS in 0.5 M H2SO4 and 1 M HCl solutions. The inhibition potentials of the aqueous extract of the palmyra palm peduncle are enhanced by its phytochemical constituents. The density functional theory was utilized to examine the BFP extract/mild steel surface mechanism's properties and to describe the inhibitor's structural nature on the corrosion process. The surface morphological alterations of metal specimens in both inhibited and uninhibited solutions were studied using scanning electron microscopy (SEM). Fourier transform infrared (FT-IR) spectroscopy was used to validate the presence of phenolic components in the BFP extract.