Magneto-Optical Kerr Effect (MOKE) magnetometry has been used to non-destructively measure the change in magnetic properties of stainless steel samples as a result of welding. While welding is used to join and repair steels, the heat input may cause undesirable changes in the base metal. Of particular interest is the precipitation or dissolution of carbide precipitates, resulting in sensitization or desensitization of the stainless steels, respectively, along with potential changes in the magnetic properties of the steel. While the state of the material within a given region can be discerned through traditional non-destructive techniques, there is also a magnetic component to the post-welded material properties. MOKE results indicate a notable difference in magnetic performance between the base materials, heat affected zones, and weld material. Non-destructive MOKE results are correlated with changes in sensitization, composition, and microstructure that have been determined through a variety of traditional, destructive metallography and magnetometry techniques.