The corrosion behavior of 304L austenitic stainless steel deposits formed via additive friction stir deposition (AFSD) was studied, including the effects of subsequent laser shock peening. Electrochemical testing and microscopic analysis show that the AFSD material has poor corrosion resistance in the as-deposited condition when the oxidized layer formed on the surface of the deposit from the high temperatures experienced during the AFSD process is present. However, following removal of the surface oxidized layer by polishing, the corrosion resistance is vastly improved and is similar to that of the baseline 304L wrought substrate material in oxidizing and simulated saline environments. LSP enhances the corrosion resistance of AFS deposits, particularly when the oxidized layer formed on the surface of the deposit is removed. However, when the oxidized layer remains, regardless of LSP treatment, corrosion resistance is poor due to the oxide hindering passivation. These findings highlight the similarity in corrosion performance between AFS deposits and baseline commercial 304L, the effectiveness of LSP in enhancing passivity, and the importance of surface polishing.