A control apparatus for a rotating electric machine is applied to a rotating electric machine system. The rotating electric machine system includes a rotating electric machine having a multiple-phase winding, a first inverter connected to a first end of the winding for each phase, a second inverter connected to a second end of the winding for each phase, a high-potential-side connection line, and a low-potential-side connection line. The control apparatus acquires a parameter that has a correlation with a fundamental current that flows to the winding of each phase. The control apparatus stores, in a storage unit, correspondence information in which the parameter is associated with an amplitude and a phase of a harmonic voltage that is generated in the rotating electric machine. The control apparatus controls each of the first inverter and the second inverter to suppress the harmonic voltage based on the correspondence information and the acquired parameter.