2D nanoscale oxides have attracted a large amount of research interest due to their unique properties. Here, a facile synthetic approach to prepare graphene‐mimicking, porous 2D Co 3 O 4 nanofoils using graphene oxide (GO) as a sacrificial template is reported. The thermal instability of graphene, as well as the catalytic ability of Co 3 O 4 particles to degrade carbon backbones, allow the fabrication of porous 2D Co 3 O 4 nanofoils without the loss of the 2D nature of GO. Based on these results, a graphene mimicking as a route for large‐area 2D transition metal oxides for applications in electrochemical energy storage devices is proposed. As a proof of concept, it is demonstrated that graphene‐like, porous 2D Co 3 O 4 nanofoils exhibit a high reversible capacity (1279.2 mAh g −1 ), even after 50 cycles. This capacity is far beyond the theoretical capacity of Co 3 O 4 based on the conversion mechanism from Co 3 O 4 to Li 2 O and metallic Co.