We report a KOH self-templating synthesis of three-dimensional hierarchical porous carbon using resol as the precursor and KOH as both the template and activating agent. The resulting resol-derived porous carbon (RPC) exhibits a high surface area (up to 2700 m² g⁻¹) and well-interconnected macropores with micropores and mesopores decorated on the carbon walls. Consequently, the RPC shows low internal resistance, high specific capacitance, good rate capability and excellent cycling stability in 6 M KOH as a supercapacitor electrode. Because of its easy fabrication and low cost, it offers a good alternative method for synthesis of carbon electrodes for energy-storage devices such as Li-ion batteries, fuel cells and supercapacitors.