An engineered iodine catalysis for the light‐promoted homolytic C‐H bond cleavage provides straightforward access to aliphatic fluorination. The intermediary formation of amidyl radicals enables selective C‐H functionalization via carbon‐centered radicals. For the subsequent C‐F bond formation, previous methodology is typically limited to the use of electrophilic fluorine reagents. We here demonstrate that the intermediary instalment of a carbon‐iodine bond sets the strategic basis for an Umpolung and thereby establishes an unprecedented nucleophilic fluorination pathway.