Abstract: | Heteroaromatic sulfoxides are a frequent structural motif in natural products, drugs, catalysts, and materials. We report a metal‐free visible‐light‐accelerated synthesis of heteroaromatic sulfoxides from sulfinamides and peroxodisulfate. The reaction proceeds at room temperature with blue‐light irradiation and allows the C?H sulfinylation of electron‐rich heteroarenes, such as pyrroles and indoles. An electrophilic aromatic substitution mechanism is proposed based on the substrate scope, substitution selectivity, and competition experiments with different nucleophiles. |