Increasing energy demands, depletion of fossil fuels, and environmental issues have impelled society to choose the pathways of renewable and clean energy, which motivated scientists and engineers to develop sustainable, renewable, and clean energy resources. However, the major challenge is the implementation of low‐cost, flexible approaches and materials to fulfill the requirements of energy storage and conversion technologies, specifically those involving batteries and supercapacitors. In this context, herein, we demonstrate an integrated approach to realize three‐dimensional (3‐D) mesoporous nickel(Ni)/nickel oxide (NiO) nanostructures with enhanced performance for supercapacitor applications. Conformal deposition of NiO nanoflakes on 3‐D mesoporous Ni onto inexpensive Cu substrates with large active surface area, providing easy ion accessibility through mesoporous channels and improving