A lighting device includes an annular light source including light sources arranged in a circular pattern, a light guide plate having a round shape in a plan view, and a case holding the annular light source and the light guide plate. The light guide plate is disposed inside the annular light source. The light guide plate includes light entering portions, circumferentially aligned portions, and a light emitting portion. The light entering portions are opposed to the light sources. Each circumferentially aligned portion is between the adjacent light entering portions. A dimension of the circumferentially aligned portion in the radial direction is larger than a dimension of the light entering portion in the radial direction. The circumferentially aligned portions are aligned with the light sources in the circumferential direction and configured to contact the light sources when the light guide plate is rotated in the circumferential direction.