The radical difunctionalization of unsaturated hydrocarbons serves as an efficient means to rapidly construct molecular skeletons and synthesize‐highly valuable compounds. In this transformational process, diverse positions within unsaturated hydrocarbons are sequentially functionalized by a single radical precursor reagent, thereby achieving highly efficient and selective transformations that promote atom economy. Furthermore, this approach minimizes the generation of numerous byproducts stemming from cross‐coupling reactions between reactants, owing to the reduction of the number of participating components. Therefore, this review provides an in‐depth analysis of the radical difunctionalization of unsaturated hydrocarbons utilizing a single functional reagent in recent decades. The discussion is based on eight different radical classes (carbon‐, nitrogen‐, phosphine‐, oxygen‐, sulfur‐, selenium‐, tellurium‐, and chlorine‐centered radicals), emphasizing the mechanism of specific radical difunctionalization. It also analyzes in detail the regulation of key factors such as regional selectivity, and provides unique insights into reaction transformations.