Supercapacitors based on freestanding and flexible electrodes that can be fabricated with bacterial cellulose (BC), multiwalled carbon nanotubes (MWCNTs), and polyaniline (PANI) are reported. Due to the porous structure and electrolyte absorption properties of the BC paper, the flexible BC-MWCNTs-PANI hybrid electrode exhibits appreciable specific capacitance (656 F g−1 at a discharge current density of 1 A g−1) and remarkable cycling stability with capacitance degradation less than 0.5% after 1000 charge–discharge cycles at a current density of 10 A g−1. The facile and low-cost of this binder-free paper electrode may have great potential in development of flexible energy-storage devices.