Given the increasing demand for diverse alkyl fluorides for various applications, it would be beneficial to enrich the fluorination toolbox by including more kinds of common functional groups, such as ketones, as fluoride surrogates. Here we report a Cu-mediated deacylative fluorination approach that can convert a wide range of methyl ketones to the corresponding alkyl fluorides. The reaction is enabled by a ketone activation reagent and a nucleophilic fluoride source. It features broad functional group tolerance, capability for the late-stage fluorination, fluoro-annulation, synthesis of α,α-dideuterated fluorides, and degree-controlled synthesis of mono-, di-, and trifluoro alkanes from a single ketone starting material. The computational studies suggest interesting Cu(III)-mediated C–F bond forming pathways via either fluorine atom transfer or an SN2 process.