An image sensor includes a substrate including a first surface and a second surface, a first transmission gate electrode on the first surface of the substrate, a storage node on the first surface of the substrate and including a first storage gate electrode isolated from direct contact with the first transmission gate electrode, a dielectric layer on the first storage gate electrode, and a semiconductor layer on the dielectric layer. The image sensor may include a first cover insulating layer on the semiconductor layer and vertically overlapping the first transmission gate electrode, and an organic photoelectric conversion layer on an upper surface of the semiconductor layer and an upper surface of the first cover insulating layer.