The dual function of the N‐F bond as an effective oxidant and subsequent nitrogen source in intramolecular aliphatic C‐H functionalization reactions is explored. Copper catalysis is demonstrated to exercise full regio‐ and chemoselectivity control, which opens new synthetic venues to nitrogenated heterocycles with predictable ring size. For the first time, a uniform catalysis manifold has been identified for the construction of both pyrrolidine and piperidine cores. The individual steps of this new copper oxidation catalysis are elucidated by control experiments and computational studies, clarifying the singularity of the N‐F function and characterizing the catalytic cycle to be based on a copper(I/II) manifold.