Abstract The palladium/norbornene co‐catalyzed difunctionalization of haloarenes provides a facile and efficient method for the synthesis of polyfunctional aromatic compounds. However, the suitable substrates for such a transformation have been strictly limited to haloarenes. We here demonstrate that aryl diazonium salts could be well employed as substrates in these reactions, enabling arylbromides with electron‐withdrawing groups to be used as cross‐coupling partners.