A hierarchical NiO/NiMn-LDH nanosheet array on Ni foam was prepared via a facile two-step approach and exhibited a high specific capacitance (937 F g-1 at 0.5 A g-1) and good cycling stability (91% retention after 1000 cycles at 5 A g-1). The improved electrochemical performance is benefited from the synergistic properties of hierarchical NiO/LDH nanosheet composites on a conductive substrate.