In this work, electrochemical and surface characteristics of 316L stainless steel manufactured by laser powder bed fusion (LPBF) were studied in the 0.1 M H2SO4 solution containing methionine as a corrosion inhibitor. Electrochemical studies such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and adsorption isotherm, and characterization methods such as field emission scanning electron microscopy integrated with an energy dispersive x-ray spectroscopy (FESEM‐EDS), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS) were performed to evaluate the effect of the inhibitor on the corrosion behavior of LPBF processed stainless steel. FESEM micrographs of the LPBF processed alloy showed the presence of cellular/columnar morphology, most probably due to the effect of a high cooling rate during the LPBF process. The results of the electrochemical tests indicated that the charge transfer resistance of stainless steel in the presence of methionine increases from 4810 up to 13,300 Ω cm2, and Ecorr shifted about 250 mV toward the noble direction. Besides, corrosion current density decreases from 3.24 to 0.45 μA cm−2 as the concentration of methionine increases from 0 to 500 ppm in the sulfuric acid. Adsorption isotherm revealed a physical-chemical interaction of inhibitor with the surface. It is assumed that the methionine can adsorb on the anodic sites of the alloy during the immersion period and block the immigration of aggressive species toward the surface.