To provide a vehicle vibration attenuation device capable of suppressing the deterioration of the ground contact property of a tire and riding comfort due to an increase in unsprung mass.

The vehicle vibration attenuation device 1 includes an electric motor 22 suspended by a bracket 14, which is an unsprung member, in a vertically oscillatable manner by the use of a coil spring 23 and a damper 24, a reducer 21 reducing the rotational speed of the electric motor 22, and a power transmitting means 26 transmitting power between the electric motor 22 and the reducer 21. Since the electric motor 22 is suspended in the vertically oscillatable manner by the coil spring 23 and the damper 24, the electric motor 22, the coil spring 23, and the damper 24 function as a dynamic damper reducing the vibration of the unsprung member.