A steering device includes a motor; a steering shaft; a belt transmission mechanism including a drive pulley, a driven pulley, and a belt; a housing that accommodates the belt transmission mechanism; and a pulley holder that holds the motor and is attached to the housing so as to rotatably support the drive pulley. The pulley holder includes a first supporting portion that supports a first shaft portion of the drive pulley and a second supporting portion that supports a second shaft portion of the drive pulley. The steering device further includes a pulley holder supporting portion that supports a portion, of the pulley holder, located closer to the second supporting portion than the center of the pulley portion in relation to the housing.