Herein, a direct C8‐arylation reaction of 1‐amidonaphthalenes is described. By using diaryliodonium salts as arylating agents, the palladium‐catalyzed C−H activation reaction showed perfect C8 regioselectivity and a wide functional group tolerance. In most cases, the desired polyaromatic compounds were isolated in good to excellent yields. To explain the observed regioselectivity, DFT calculations were performed and highlighted the crucial role of the amide directing group. Finally, the utility of this method is showcased by the synthesis of benzanthrone derivatives.