Although direct formic acid fuel cells and direct methanol fuel cells have attracted a lot of interest owing to their high energy‐conversion efficiency and low pollutant emissions, their large‐scale commercial applicability is limited by lack of suitable catalysts that exhibit high activity and are cheap. Here, a synergistic morphology and defect engineering strategy for the “clean” synthesis of multiple‐twinned Pd nanoparticles on nitrogen‐doped low‐defect graphitic carbon nanosheets (Pd/NL‐GCN) without using a template or surfactant are presented. The unique grain‐boundary‐enriched multiple‐twinned Pd nanoparticles provide a large number of catalytically active sites, while the graphitic carbon frameworks with a modulated electronic structure afford high electron conductivity as well as strong poison tolerance. Consequently, the Pd/NL‐GCN hybrid shows outstanding catalytic performance with respect to the oxidation of formic acid and methanol, exhibiting a large electrochemically active surface area, high mass activity, and good long‐term durability. Moreover, the catalyst outperforms conventional Pd‐nanoparticle‐based catalysts supported on carbon black, carbon nanotubes, and graphene materials.