A control apparatus is applied to a hybrid vehicle including an internal combustion engine that is capable of changing over its combustion state between lean combustion and stoichiometric combustion. The control apparatus executes noise suppression control by limiting the operating point of the internal combustion engine to be upon a noise suppression line for lean combustion or to be upon a noise suppression line for stoichiometric combustion, so that the noise generated by a power transmission mechanism is suppressed. When changing over from lean combustion to stoichiometric combustion during execution of noise suppression control, the control apparatus of the present invention changes the air/fuel ratio after changing the operating point of the internal combustion engine from one point to a point that is more toward the lower torque side of the noise suppression line.