Manganese dioxide nanosheet arrays with interconnected arrangements are easily synthesized on vapor grown carbon fibers (MnO₂ NSAs@VCFs) by a simple wet-chemical method at low temperature. The conductive nature of the VCFs serves as a scaffold and easily reduces potassium permanganate species for the formation of hierarchical MnO₂ NSAs@VCFs. When utilized as an electroactive material for pseudocapacitors, the sophisticated configuration of the nanocomposite provides an effective electrochemical activity and an electron pathway for higher electrochemical performance in 1 M Na₂SO₄ aqueous solution. The hierarchical MnO₂ NSAs@VCFs exhibit a maximum specific capacitance of 115.3 F g⁻¹ at a current density of 0.5 A g⁻¹ with an excellent cycling stability of 85.6% after 2000 cycles at a current density of 5 A g⁻¹. Such facile and cost-effective fabrication of a metal oxide nanocomposite with improved electrochemical performance allows it to be considered as a promising electroactive material for energy storage devices.