Application of trans‐3,5‐dihydroperoxy‐3,5‐dimethyl‐1,2‐dioxolane as an efficient and high‐ oxygen content reagent in selective oxidation of sulfides into sulfoxides has been successfully explored. The reactions proceeded under mild and catalyst‐free conditions in dichloromethane at room temperature to provide the sulfoxides in excellent yields without any significant over‐oxidation to sulfones.