Fast charge‐discharge rate and high areal capacitance, along with high mechanically stability, are the pre‐requisites for flexible supercapacitors to power flexible electronic devices. In this paper, we have used three‐dimensional polyacrylonitrile graphite foam as flexible current collector for electro‐deposition of polyaniline (PANI) nanowires. The graphite foam with PANI was then used to fabricate symmetric supercapacitor. The fabricated supercapacitor in the three‐electrode system shows a high specific capacitance (Csp) of 357 F.g−1 and areal capacitance (Careal) of 7142 mF.cm−2 in 1 M H2SO4 at current density of 80 mA.cm−2, while using two‐electrode system, it shows Csp of 256 F.g−1 and Careal of 5120 mF.cm−2 in 1 M H2SO4 at current density of 100 mA.cm−2. The current density of 100 mA.cm−2 is up to 10 folds higher than reported current densities of many PANI‐based supercapacitors. The high capacitance can be attributed to the spongy network of PANI‐NWs on three‐dimensional graphite surface which provides an easy path for electrolyte ions in active electrode materials. The developed supercapacitor shows specific energy of 64.8 Whkg−1 and a specific power of 6.1 kWkg−1 with a marginally decrease of 1.6% in Csp after 1000th cycles, along with coulombic efficiency retention of 87% in polyvinyl alcohol/H2SO4 gel electrolyte. This flexible supercapacitor exhibits great potential for energy storage application.