HCl in solution accepts electron density from Au NPs and partially reduces at room temperature, as occurs with other simple diatomic molecules, such as O2 and H2. The activation can be run catalytically in the presence of alkynes to give exclusively E‐vinyl chlorides, after the regio‐ and stereoselective transfer of HCl. Based also on this method, vinyl chloride monomer (VCM) can be produced in a milder and greener way than current industrial processes. A helping hand from gold: Hydrogen chloride is partially reduced by supported gold nanoparticles at room temperature. It is catalytically added to alkynes to give, regio‐ and stereoselectively, E‐α‐vinyl chlorides. This approach enabled the synthesis of vinyl chloride monomer from acetylene in continuous mode.