Direct and selective transformation of the phenolic hydroxy group in a concise way without prior derivatization is relevant in many industrial processes, particularly late-stage modification of pharmaceuticals and for lignin-material treatment. The introduction of fluorine has a profound impact on the molecular properties of both small molecules and biopolymers. Herein, we report a Ru-catalyzed transformation of phenols into trifluoromethyl-arenes under mechanochemical conditions. The protocol accepts a wide scope of starting materials and allows for gram-scale synthesis in excellent yields. The developed approach may offer an important alternative to known methods in the context of PASE (pot, atom, and step economy) synthesis and, therefore, green chemistry.