Highly activated porous carbon materials with unique architecture, heteroatom incorporation, substantial specific surface area, and promising electrochemical properties are regarded as superior electrode materials for supercapacitor applications. In this study, we synthesized activated porous nitrogen-doped carbon (APNC) using a nitrogen-containing isonicotinic acid organic ligand within a Zn-based metal–organic framework (Zn-MOF) as both a source and template through a facile pyrolysis process with KOH activation. The resulting APNC material with the optimized sythesis conditions exhibited uniform polyhedral morphology, a large specific surface area (1947.9 m 2 g −1 ), extensive pore volume (2.05 cm 3 g −1 ), and nitrogen heteroatom doping in the carbon framework. These features collectively enhanced its electrochemical performance and ensured exceptional electrochemical stability in a 6 M KOH electrolyte. Electrochemical measurements in a three-electrode setup revealed that the synthesized APNC electrode material accomplished a specific capacitance of 360 F g −1 at 1 A g −1 . In addition, APNC proved excellent cycling stability, retaining 95.5% of its capacitance after 50,000 cycles at a high current density of 20 A g −1 . Moreover, a coin cell–type symmetric supercapacitor fabricated with APNC delivered an brilliant energy density of 18.2 Wh kg −1 at a power density of 400 W kg −1 . This study highlights the ability of APNC to serve as an inexpensive and highly effective electrode material, establishing its potential for high-performance supercapacitors in practical applications.