Vehicle seat belt apparatus includes: a motor for driving a belt reel having a belt wound thereon; a trigger section for detecting a change in a traveling state of a vehicle to output an activation signal that instructs or triggers activation of the motor; a lateral acceleration detection section for detecting lateral acceleration acting on the vehicle; a slip state detection section for detecting a slip state quantity of the vehicle; and a control section for, in response to receipt of the activation signal from the trigger section, controlling the amount of current supply for activating the motor on the basis of a signal of the lateral acceleration output by the lateral acceleration detection section and/or a signal of the slip state quantity output by the slip state detection section.