The Cp*Ir-catalyzed C 8 -selective arylation of quinoline N -oxides with arylsilanes is developed. This C-H activation transformation can be carried out under mild reaction conditions in good yields with a broad substrate scope and excellent functional-group tolerance. This protocol can be easily used to synthesize diverse quinoline derivatives and enable the late-stage modification of quinoline drugs. A plausible reaction mechanism is elucidated based on a series of preliminary mechanistic studies.