A control device (40, 50) for a vehicle, the control device comprising control circuits (41, 42; 51, 52) of a plurality of systems that calculate a current command value according to torque to be generated by a motor (21; 31) including winding groups (N11, N12; N21, N22) of a plurality of systems, and control electric power supply to the winding groups of the systems independently for each system based on the calculated current command value, wherein: the control circuits (41, 42; 51, 52) of the systems have a master-slave relationship, and have a first driving mode in which electric power supply to the winding groups of the control circuits' own systems is controlled by using a current command value calculated by the control circuit serving as a master, and a second driving mode in which current command values personally calculated by the control circuits are adjusted and electric power supply to the winding groups of the control circuits' own systems is controlled based on the adjusted current command values; when a predetermined transition condition is established, the control circuits of the systems make transition of a driving mode from the first driving mode to the second driving mode, and when a predetermined return condition is established in a state in which the driving mode has transitioned to the second driving mode, the control circuits of the systems make transition of the driving mode from the second driving mode to the first driving mode while gradually changing the current command values of the control circuits' own systems toward the current command value before the adjustment; the control circuit (42; 52) serving as a slave calculates a current command value of the control circuit serving as the slave's own system by multiplying a current command value personally calculated by the control circuit serving as the slave and the current command value calculated by the control circuit serving as the master by distribution gains that are individually set to define a distribution ratio and adding results obtained from the multiplication; and when the return condition is established in the state in which the driving mode has transitioned to the second driving mode, the control circuit serving as the slave gradually decreases a value of the distribution gain for the current command value personally calculated by the control circuit serving as the slave, and gradually increases a value of the distribution gain for the current command value calculated by the control circuit serving as the master. the control circuits (41, 42; 51, 52) of the systems have a master-slave relationship, and have a first driving mode in which electric power supply to the winding groups of the control circuits' own systems is controlled by using a current command value calculated by the control circuit serving as a master, and a second driving mode in which current command values personally calculated by the control circuits are adjusted and electric power supply to the winding groups of the control circuits' own systems is controlled based on the adjusted current command values; when a predetermined transition condition is established, the control circuits of the systems make transition of a driving mode from the first driving mode to the second driving mode, and when a predetermined return condition is established in a state in which the driving mode has transitioned to the second driving mode, the control circuits of the systems make transition of the driving mode from the second driving mode to the first driving mode while gradually changing the current command values of the control circuits' own systems toward the current command value before the adjustment; the control circuit (42; 52) serving as a slave calculates a current command value of the control circuit serving as the slave's own system by multiplying a current command value personally calculated by the control circuit serving as the slave and the current command value calculated by the control circuit serving as the master by distribution gains that are individually set to define a distribution ratio and adding results obtained from the multiplication; and when the return condition is established in the state in which the driving mode has transitioned to the second driving mode, the control circuit serving as the slave gradually decreases a value of the distribution gain for the current command value personally calculated by the control circuit serving as the slave, and gradually increases a value of the distribution gain for the current command value calculated by the control circuit serving as the master.