In recent times, the sulfate radical anions (SO4•−) are largely being utilized for the functionalization of drugs (taxol, pregabalin, nicotine, etc.) and synthesis of various organic compounds including heterocyclic compounds, fertilizers, nanoparticles, and polymers. Moreover, they are also employed for the destruction of a variety of organic contaminants such as perfluoro carboxylic acids, chlorinated solvents, polycyclic aromatic hydrocarbons, textile dyes, pharmaceuticals, xylenes, and so on. SO4•− have a very strong one-electron oxidation potential, i.e., 2.43 V vs. NHE in aqueous solutions, and they are well generated through the scission of the peroxide bond of persulfates. To date, some important reviews are available that 2summarize the metal-catalyzed productions of SO4•− and their applications toward organic functional group transformations as well as the extinction of organic pollutants. To the best of our knowledge, however, there is still no article exclusively discourses about the transition metal-free formation of SO4•− in aqueous solutions and their applications for the organic synthesis and functional group transformations. Therefore, in this chapter, we provide an overview of the transition metal-free protocols deal with the generation of SO4•− from persulfates in aqueous media. Also, we highlight the utilization of in situ formed SO4•− toward syntheses and functionalization of various small organic molecules.