A chlorofluorocarbon (CFC) is an organic compound that contains only carbon, chlorine, hydrogen and fluorine, produced as a volatile derivative of methane and ethane. They are also commonly known by the DuPont brand name Freon. The most common representative is dichlorodifluoromethane (R-12 or Freon-12). Many CFCs have been widely used as refrigerants, propellants (in aerosol applications), and solvents. The manufacture of such compounds has been phased out (and replaced with products such as R-410A) by the Montreal Protocol because they contribute to ozone depletion in the upper atmosphere.

As in simpler alkanes, carbon in the CFCs and the HCFCs is tetrahedral. Since the fluorine and chlorine atoms differ greatly in size from hydrogen and from each other, the methane derived CFCs deviate from perfect tetrahedral symmetry.

The physical properties of the CFCs and HCFCs are tunable by changes in the number and identity of the halogen atoms. In general they are volatile, but less so than parent alkane. The decreased volatility is attributed to the molecular polarity induced by the halides and the polarizability of halides, which induces intermolecular interactions. Thus, methane boils at −161 °C whereas the fluoromethanes boil between −51.7 (CF₂H₂) and −128 °C (CF₄). The CFCs have still higher boiling points because the chloride is even more polarizable than fluoride. Because of their polarity, the CFCs are useful solvents. The CFCs are far less flammable than methane, in part because they contain fewer C-H bonds and in part because, in the case of the chlorides and bromides, the released halides quench the free radicals that sustain flames.