Due to their combined performance of faradic reaction and electrostatic charge accumulation mechanisms, composites of carbon and conductive polymers are prominent supercapacitor electrodes. However, low-cost efficient carbon materials to couple with conductive polymer remain a challenge for supercapacitor applications. Here, we report the fabrication of heteroatoms (Mg, Si, P, S, Cl, Ca, Fe, and N)-enriched hierarchical porous carbon by directly pyrolyzing the filaments of Pithophora polymorpha without chemical activation and successive electrodeposition of polyaniline on the prepared carbon. The resulting composite was used as a supercapacitor electrode that showed pseudocapacitor behavior (i.e., redox-based cyclic voltammograms), a high areal capacitance of 176 mF/cm² at 1 mA/cm², and maintained 95% of its initial capacitance after 1000 charge/discharge cycles. The composite electrode was capable to supply high energy density of 24.5 μWh/cm² corresponding to a high-power density of 500 μW/cm². The advanced capabilities of the composite electrode towards high-performance electrochemical energy storage may be attributed to the unique redox-active behavior of polyaniline, the active framework of porous heteroatoms-enriched hierarchical carbon, and improved electrical conductivity of the composite. This approach may provide a promising avenue to develop high-performance composite electrodes for supercapacitors from scalable, biological, and inexpensive biomass precursors, Pithophora polymorpha.