The effectiveness of sodium dodecyl sulfate (SDS) is investigated as an inhibitor against a 0.5 M H ₂ SO ₄ solution on mild steel (MS). The method was conducted for the calculation of critical micelle concentration (CMC) calculation, weight loss and potentiodynamic polarization. The SDS-coated steel samples were characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray energy dispersive spectroscopy and atomic force microscopy to understand the surface morphologies after exposure to the CMC of SDS solution. Conductivity measurements were performed to determine the CMC of the SDS solution. It appears that SDS is a perfect inhibitor of MS corrosion, as the weight loss measurement result found an inhibition efficiency of SDS of approximately 98.37% in 0.5 M H ₂ SO ₄ solution. We also found, from the Tafel plot, a corrosion current of 0.98 × 10 ⁻³ A cm ⁻² at CMC (0.0077 M), when MS was dipped for 9 h in 0.5 M H ₂ SO ₄ . SDS enhances the corrosion resistance of MS in acidic environments and its potential implications for industrial applications. It varies with SDS concentrations, which is attributed to the development of a protective Fe ²⁺ –SDS complex on the MS surface.