Reactions of electron-rich (hetero)arenes with [Me₄N][SeCF₃] in the presence of an oxidant gave a variety of trifluoromethylselenolated products in good to high yields. The reaction is easy to handle and proceeds smoothly under metal-free conditions without using harsh and toxic reagents. Advantages of the reaction also include a wide range of substrates, good functional group tolerance, readily available starting materials, excellent regioselectivity of the products, and compatibility of various cheap oxidants. It is significant to find out that the moisture- and air-sensitive [Me₄N][SeCF₃] reagent could be successfully utilized in aqueous media or under an ambient atmosphere, which are very important additions to the previous acquirements of the ⁻XCF₃ (X = O, S, Se) species. This protocol has allowed the synthesis of a large number of drug-like molecules and represents the first trifluoromethylselenolation of nucleophilic (hetero)arenes with the nucleophilic [Me₄N][SeCF₃] salt under transition-metal-free conditions.