A matrix converter (38) converts three-phase AC power input from a first motor-generator (MG1) directly to three-phase AC power for driving a second motor-generator (MG2) and outputs the resultant three-phase AC power, without rectifying the three-phase AC power generated by the first motor-generator (MG1) once to DC power as in an example using a conventional three-phase full-wave rectification inverter. In a power supply system for a vehicle (14), the three-phase AC power is transmitted and received between two motor-generators (MG1, MG2) more directly, by means of the matrix converter (38). Therefore, power loss can be reduced, as compared with a conventional example in which the three-phase AC power is once converted to DC power. Thus, a power supply system for a vehicle with improved energy efficiency and a vehicle including the same can be provided.