A virtual image display system includes a display device that outputs image light, a projection lens that projects the image light from the display device, a first holding member that holds the projection lens, a light guide plate that takes in the image light from the projection lens, and then, guides the light to an external predetermined position, and a second holding member that holds the light guide plate. A positioning structure for positioning the light guide plate with respect to the projection lens is provided in the first holding member and the second holding member.