A control apparatus for an internal combustion engine, which makes it possible to ensure quick recovery of a storage amount of oxygen saturated due to a fuel cut, to restore the capacity of a catalytic converter to absorb air-fuel ratio disturbances, and to suppress torque fluctuations through prevention of overcorrection of the air-fuel ratio during normal operation. The control apparatus for an internal combustion engine according to the present invention is equipped with a proportional gain changeover unit. This unit makes a changeover in a proportional gain for proportional calculation in a downstream-side control unit for a predetermined period from a normal proportional gain to a post-fuel-cut proportional gain set larger than the normal proportional gain by a predetermined value, when a fuel cutoff unit starts cutting the fuel supply.