Pd-catalyzed meta-C-H chlorination of anilines and phenols is developed using norbornene as the mediator. Heterocycles, including indole, thiophene, and indazole, are tolerated. The identification of a new pyridone-based ligand is crucial for the success of this meta-C-H chlorination reaction. Subsequent diverse transformations of the chlorinated products demonstrate the versatility of meta-C-H chlorination.