A biosignal sensor includes a substrate, first light-emitting elements, second light-emitting elements, and light-receiving elements. The light-receiving elements are positioned individually spaced apart by different distances from the first light-emitting elements and the second light-emitting elements and receive light from the first light-emitting elements and the second light-emitting elements. The plurality of light-receiving elements are linearly or substantially linearly aligned in an X direction. The first light-emitting elements and the second light-emitting elements are located at positions different in a Y direction from positions of the plurality of light-receiving elements.
