In the present work, the nicotinic hydroxamic acid (NHA) was first presented as a more effective corrosion resistance in 1 M HCl. The reason for the selection of 1 M HCl solution is that 1 M HCl solution was used in the acid pickling and acid-cleaning processes. During these processes, the mild steel corroded. The carbonyl and the hydroxyl groups of the selected inhibitor molecule are mainly responsible for the formation of a stable five-membered chelate complex with a metal cation. Its inhibition characteristics were first researched by the electrochemical, surface morphology and quantum chemical methods. The density functional theory (DFT) with the 6−31G (d, p) basis sets were used to analyse the theoretical characteristics of inhibition for NHA. The corrosion prevention activity was utilized on the steel in 1 M HCl using a variety of electrochemical approaches, including potentiodynamic polarization measurements and EIS. In 1 M HCl solution, the maximum inhibition efficiency of 92.75% was achieved for 200 ppm concentration. The existence of multiple double bonds, as well as numerous oxygen atoms of carbonyl and hydroxyl groups of the phytochemicals, is primarily responsible for its superior anti-corrosive properties.