A motor controller configured to control a motor, the motor being configured to generate a torque to be applied to a steering mechanism, the motor including a plurality of winding groups, the motor being provided with a plurality of energization systems, each of the winding groups being included in a corresponding one of the energization systems, the motor controller comprising a plurality of processors (51; 61), each of the processors (51; 61) configured to independently control supply of driving electric power to each of the winding groups in the corresponding one of the energization systems, each of the processors (51; 61) being configured to calculate respective control signals based on target individual torques which is split for each of the winding groups in the corresponding one of the energization systems from a target overall torque to be generated in the motor, each of the processors (51; 61) including drive circuits configured to supply the driving electric power to each of the winding groups in the corresponding one of the energization systems based on the control signals, each of the processors (51; 61) being configured to calculate the target individual torques such that each of the target individual torques is equal to or smaller than an individual rated torque set to be smaller than an individual limit torque determined depending on a structure of the motor as a limit of a torque to be output in each of the winding groups in the corresponding one of the energization systems, each of the processors (51; 61) being configured such that, when an abnormality occurs in which a torque to be generated in one of the winding groups in the corresponding one of the energization systems is smaller than the individual rated torque and when the target overall torque is larger than a total of the individual rated torque for the winding group in the corresponding one of the energization systems in which the abnormality does not occur, the processor (51; 61), controlling supply of driving electric power to the winding group in the corresponding one of the energization systems in which the abnormality does not occur, out of the plurality of processors (51; 61) controls supply of the driving electric power such that the winding group generates a torque larger than the individual rated torque, such that deficiency of the torque to be applied from the motor can temporarily be suppressed for a short time until the motor or the drive circuit is overheated. each of the processors (51; 61) being configured to calculate respective control signals based on target individual torques which is split for each of the winding groups in the corresponding one of the energization systems from a target overall torque to be generated in the motor, each of the processors (51; 61) including drive circuits configured to supply the driving electric power to each of the winding groups in the corresponding one of the energization systems based on the control signals, each of the processors (51; 61) being configured to calculate the target individual torques such that each of the target individual torques is equal to or smaller than an individual rated torque set to be smaller than an individual limit torque determined depending on a structure of the motor as a limit of a torque to be output in each of the winding groups in the corresponding one of the energization systems, each of the processors (51; 61) being configured such that, when an abnormality occurs in which a torque to be generated in one of the winding groups in the corresponding one of the energization systems is smaller than the individual rated torque and when the target overall torque is larger than a total of the individual rated torque for the winding group in the corresponding one of the energization systems in which the abnormality does not occur, the processor (51; 61), controlling supply of driving electric power to the winding group in the corresponding one of the energization systems in which the abnormality does not occur, out of the plurality of processors (51; 61) controls supply of the driving electric power such that the winding group generates a torque larger than the individual rated torque, such that deficiency of the torque to be applied from the motor can temporarily be suppressed for a short time until the motor or the drive circuit is overheated.