A vehicle turn signal switch device whereby the production of knocking sounds by a cancellation pin when a steering wheel is turned in the direction of a turn signal is suppressed. A turn signal switch includes a fixed member and a movable plate. The cancellation pin, which is supported by the fixed member and the movable plate such that the cancellation pin can swing and move forward and backward relative to a cancellation cam, includes a sliding-contact surface that is in sliding contact with the fixed member. The cancellation pin is biased by a return spring in the direction of the cancellation cam and in the direction of the sliding contact of the sliding-contact surface with the fixed member.