A control device for a rotating electrical machine is provided that is capable of suppressing reduction in controllability of torque attributed to harmonic currents. According to the exemplary embodiment of the present invention, a designated torque value Trq* designated by a hybrid vehicle electronic control unit (HVECU) is corrected by a compensation amount ΔTrq calculated using a harmonic voltage Vh, the designated torque value Trq*, and an electric angular velocity ω as inputs. An operating signal generating section generates an operating signal g¥# using a designated norm value Vn set based on the corrected torque designated value Trq* and a phase δ serving as a manipulated variable for performing feedback control of an estimated torque to the designated torque value Trq*, and outputs the generated operating signal g¥# to a power supply circuit of a motor generator.