A new class of electrophilic monofluoromethylselenolation reagents, Se‐(fluoromethyl) benzenesulfonoselenoates, has been developed. They can be readily prepared from sodium benzenesulfinates, Se powder and ClCFH2 in one step under mild reaction conditions. Se‐(fluoromethyl) benzenesulfonoselenoates are efficient electrophilic monofluoromethylselenolation reagents for a wide range of nucleophiles including indole, 6‐azaindole, pyrrole, thiophene, electron‐rich arene, aryl boronic acid and alkyne. The monofluoromethylselenolation approach features mild and environmentally friendly reaction conditions, good tolerance of various functional groups, and broad substrate scope. [ABSTRACT FROM AUTHOR]