Aqueous Zn-ion batteries or capacitors have attracted great interest for their potential use in grid-scale energy storage systems (ESSs). They have suitable properties such as high safety, low-cost materials, and stability of Zn2+ in aqueous systems. The anode of these systems is mainly based on metallic Zn; however, corrosion of the metal surface and formation of dendrites inhibit their long-term cycle stability. It is thus necessary to find a material that can host Zn2+ in a low voltage range and enhance the electrochemical performance. Among various possible strategies, herein we applied nanostructuring to prepare mesoporous WO3 as anode material and compared the change in the electrochemical performance to that of bulk WO3. After unveiling the effect of the nanostructure, we conclude that the present nanomaterials show great potential as electrode materials for aqueous Zn-ion systems.