The innovation of nanomaterials for supercapacitors (SCs) presents a potentially viable solution to the energy crisis arising from our excessive dependence on fossil fuels. The present study demonstrated the hydrothermal synthesis of an environmentally sustainable and economical FeAl2O4 nanomaterial grafted on graphitic carbon nitride (g-CN) for supercapacitor applications. This study aimed to assess the supercapacitive capabilities of nanocomposite electrode material via various electrochemical tests. Upon investigation, it was discovered that FeAl2O4/g-CN nanocomposite material demonstrated a remarkable specific capacitance (1049 F g−1), energy density (29 Wh kg−1) and power density (223 W kg−1). Furthermore, the inclusion of g-CN nanosheets into the FeAl2O4/g-CN nanocomposite which increased surface area (SAA, 46 m2 g-1), leading to a decrease in charge transfer resistance by 0.73 Ω. The enhanced electrochemical performance was attributed to many factors, including an increased SAA, greater number of active regions and a nitrogen-rich structure that facilitates rapid ion adsorption. The FeAl2O4/g-CN nanocomposite exhibited a robust pseudocapacitive characteristic and demonstrated exceptional conduction, leading to a significantly enhanced cyclic stability endurance of 40 h. Hence, the synergistic behavior of FeAl2O4/g-CN nanocomposite results in its remarkable efficiency as a proactive electrode material for energy storage purposes.