Trifluoromethyl sulfoxides are a new class of trifluoromethylthiolating reagent. The sulfoxides engage in metal‐free C−H trifluoromethylthiolation with a range of (hetero)arenes. The method is also applicable to the functionalization of important compound classes, such as ligand derivatives and polyaromatics, and in the late‐stage trifluoromethylthiolation of medicines and agrochemicals. The isolation and characterization of a sulfonium salt intermediate supports an interrupted Pummerer reaction mechanism. May I interrupt? Taking advantage of the interrupted Pummerer reaction, trifluoromethyl sulfoxides engage in the metal‐free C−H trifluoromethylthiolation of (hetero)arenes, including drug molecules and natural products. This new class of trifluoromethylthiolating reagent exploits a new strategy for trifluoromethylthiolation in which sulfonium salts are assembled and selectively deconstructed.