To provide a power supply structure to an in-wheel motor capable of wiring a power supply cord by a shortest length while allowing the movement of a wheel and capable of improving durability of the power supply cord.

A power supply structure to an in-wheel motor of a vehicle is configured by oscillatably supporting one end of each lower arm 9 at both ends of a vehicle width direction of a suspension frame 7 and oscillatably supporting a motor housing 4 with built-in in-wheel motor at the other end of each lower arm 9 via a ball joint 12. A power supply cable 13 is wired to the ball joint 12 through the inside of the suspension frame 7 and the lower arm 9, lower arm side electrodes mounted at an end of the power supply cable 13 and ball joint side electrodes formed on an outer peripheral surface of the ball joint 12 are brought into slidable contact with each other, and the power supply cable 13 extended from the ball joint side electrodes is connected to the in-wheel motor through the inside of the ball joint 12.