Abstract 2,5‐Furandicarboxylic acid (FDCA) synthesis holds significant importance for both bio‐polymer production and emerging sustainable bio‐based alternatives for environmental and energy applications. Here, a metal‐free carbonaceous material—that is, biomass substrate 5‐hydroxymethylfurfural‐derived graphene‐like nitrogen doped porous carbon sheet (GNPCH)—and its application as a new catalyst for electrochemical FDCA synthesis is presented. The study scrutinized the catalytic principles, demonstrated the surprising robustness, and explored the origin of the high efficiency of GNPCH catalyzed electro‐synthesis of FDCA. Initially, facial pyrolysis of 5‐hydroxymethylfurfural and urea forms ultrathin GNPCH with rich micropores and defects. By employing GNPCH‐900 catalyst, stable, continuous operation of >400 h with both FDCA yields and Faraday efficiencies >90% is achieved; those values not only represent the best metal‐free catalyst and that are comparable to those of the state‐of‐the‐art metal‐based counterparts, but also showcase one of the longest‐running electrochemical FDCA synthesis reactions. A series of electrochemical measurements, in situ characterization, and density functional theory calculations indicate that the origin of the high efficiency is mainly from the pyridinic‐N‐related active sites and clarify the reaction pathway. These findings suggest that the GNPCH catalyst will be a potential alternative to the metal‐based catalysts in electrochemical biomass valorization.