A vehicle lighting fixture comprising: a light guide portion; and at least one light source configured to emit light that is allowed to enter the light guide portion, the light guide portion including a light guide plate formed in a circular arc shape and having a first end portion, a second end portion, a front light emission surface extending between the first end portion and the second end portion in a circular arc shape, a rear surface opposite to the front light emission surface, an inner peripheral surface, an outer peripheral surface, a plurality of lens cut surfaces (20c1) formed in the front light emission surface to extend in a circular arc shape, the lens cut surfaces (20c1) being recessed rearward and formed in a concentric manner, and a structural body (20d1) provided to the rear surface of the light guide plate, the structural body (20d1) being configured to diffuse and reflect light guided within the light guide plate in order for the light to exit through the front light emission surface, the vehicle lighting fixture being characterized in that the front light emission surface of the light guide plate is shaped such that an outer side thereof is located more rearward than an inner side thereof, the rear surface of the light guide plate is shaped such that an outside thereof is located more rearward than an inner side thereof, the light guide plate is formed in a substantially circular truncated conical shape where a part of the light guide plate on an outer peripheral side is located more rearward than a part of the light guide plate on an inner peripheral side, and a portion defined by the light emission surface and the rear surface of the light guide plate has a plate shape. a light guide portion; and at least one light source configured to emit light that is allowed to enter the light guide portion, the light guide portion including a light guide plate formed in a circular arc shape and having a first end portion, a second end portion, a front light emission surface extending between the first end portion and the second end portion in a circular arc shape, a rear surface opposite to the front light emission surface, an inner peripheral surface, an outer peripheral surface, a plurality of lens cut surfaces (20c1) formed in the front light emission surface to extend in a circular arc shape, the lens cut surfaces (20c1) being recessed rearward and formed in a concentric manner, and a structural body (20d1) provided to the rear surface of the light guide plate, the structural body (20d1) being configured to diffuse and reflect light guided within the light guide plate in order for the light to exit through the front light emission surface, the vehicle lighting fixture being characterized in that the front light emission surface of the light guide plate is shaped such that an outer side thereof is located more rearward than an inner side thereof, the rear surface of the light guide plate is shaped such that an outside thereof is located more rearward than an inner side thereof, the light guide plate is formed in a substantially circular truncated conical shape where a part of the light guide plate on an outer peripheral side is located more rearward than a part of the light guide plate on an inner peripheral side, and a portion defined by the light emission surface and the rear surface of the light guide plate has a plate shape.