Illuminating device, display device, and mobile electronic apparatus

An illuminating device comprising:

• a first light-emitting element;
• and
• a light-guide plate including on a side surface thereof a first light-incident portion opposing the first light-emitting element, and configured to emit illumination light from a surface on one side in a thickness direction, wherein
• the light-guide plate in plan view has a shape having a curved surface on the side surface thereof at a distance from the first light-incident portion, and
• a plurality of first bevels facing the first light-incident portion at a certain angle exceeding (90°—critical angle) with respect to a virtual line extending from a center of the first light-incident portion are provided in at least part of an area of the curved surface in a circumferential direction in plan view.