An opening and closing body control apparatus for a vehicle includes an assist control portion detecting an operation of an opening and closing body configured to be provided at the vehicle, controlling voltage applied to a motor serving as a drive source, and applying a drive force to the opening and closing body in a direction in which the operation of the opening and closing body is assisted. The assist control portion applies an assist voltage and an offset voltage alternately to the motor to operate an assist control for applying the drive force to the opening and closing body, the assist voltage for rotating the motor at a rotation speed which corresponds to an operation speed of the opening and closing body, the offset voltage which is lower than the assist voltage.