Attaining absolute control over a catalytic process and, therewith, exploiting its full potential pleases scientists in their ambitious and ongoing endeavor to perform catalysis like Nature does. In this regard, redox-switchable catalysis certainly holds great potential, constantly gaining importance in modern catalysis research. Herein, we report the application of P-stereogenic dendritic ferrocenyl phosphines in the ruthenium-catalyzed redox-switchable transfer hydrogenation of a ketone yielding an enantioenriched alcohol. By adding a chemical oxidant or reductant, the catalytic activity of the complexes was reversibly switched off and back on again over the course of the hydrogen transfer reaction. This has been rationalized mainly in terms of a distinct electronic communication between the redox-active group and the catalytic center. The highly functionalized dendritic catalysts presented here might impact the way prospective homogeneous catalysts will be designed.