In recent decades, rechargeable Mg batteries (RMBs) technolo-gies have attracted much attention because the use of thin Mgfoil anodes may enable development of high-energy-densitybatteries. One of the most critical challenges for RMBs is findingsuitable electrolyte solutions that enable efficient and reversibleMg cells operation. Most RMB studies concentrate on thedevelopment of novel electrolyte systems, while only fewstudies have focused on the practical feasibility of using puremetallic Mg as the anode material. Pure Mg metal anodes havebeen demonstrated to be useful in studying the fundamentalsof nonaqueous Mg electrochemistry. However, pure Mg metalmay not be suitable for mass production of ultrathin foils(<100 microns) due to its limited ductility. The metals industryovercomes this problem by using ductile Mg alloys. Herein, thefeasibility of processing ultrathin Mg anodes in electrochemicalcells was demonstrated by using AZ31 Mg alloys (3% Al; 1%Zn). Thin-film Mg AZ31 anodes presented reversible Mgdissolution and deposition behavior in complex ethereal Mgelectrolytes solutions that was comparable to that of pure Mgfoils. Moreover, it was demonstrated that secondary Mg batteryprototypes comprising ultrathin AZ31 Mg alloy anodes(█25 m thick) and MgxMo6S8Chevrel-phase cathodes exhib-ited cycling performance equal to that of similar cells contain-ing thicker pure Mg foil anodes. The possibility of usingultrathin processable Mg metal anodes is an important step inthe realization of rechargeable Mg batteries.