An iron‐catalyzed denitrogenative rearrangement of 1,2,3,4‐tetrazole is developed over the competitive C(sp3)–H amination. This catalytic rearrangement reaction follows an unprecedented metalloradical activation mechanism. Employing the developed method, a wide number of complex‐N‐heterocyclic product classes have been accessed. The synthetic utility of this radical activation method is showcased with