A control apparatus for a multicylinder internal combustion engine includes: a detection portion that detects a parameter that represents degree of variation in air/fuel ratio among cylinders; a measurement portion that measures stored oxygen amount of a catalyst provided in an exhaust passageway of the internal combustion engine; and a rich-control portion that switches between execution and stop of a rich control for enriching the air/fuel ratio according to the stored oxygen amount measured by the measurement portion when the parameter detected by the detection portion is greater than or equal to a predetermined value.