A control apparatus for an internal combustion engine includes a turbocharger, a bypass passage, a waste gate valve, a turbo bypass valve, an air-fuel ratio sensor and an electronic control unit. The air-fuel ratio sensor is provided in an exhaust passage downstream of a merging point at which the bypass passage merges with the exhaust passage. The electronic control unit is configured to, when a predetermined acceleration request is established and a required opening degree of the turbo bypass valve is larger than a predetermined reference opening degree, execute air-fuel ratio control for changing an air-fuel ratio of exhaust gas from the internal combustion engine for a predetermined first period, and close the waste gate valve based on a convergence status of detected air-fuel ratio fluctuations. The detected air-fuel ratio fluctuations are fluctuations in air-fuel ratio that is detected by the air-fuel ratio sensor resulting from the air-fuel ratio control.