An image sensor includes a substrate including a pixel region and a peripheral circuit region, and a first device isolation layer disposed in the substrate to define a plurality of unit pixels that are adjacent to each other in a first direction in the pixel region. Each of the plurality of unit pixels includes at least one light sensing element disposed in the substrate. The image sensor includes an interlayer insulating structure on the substrate, and a first blocking structure disposed on the first device isolation layer and penetrating the interlayer insulating structure. The first blocking structure is disposed between the plurality of unit pixels when viewed from a plan view. The first blocking structure extends in a second direction intersecting the first direction when viewed from a plan view.