The present technology relates to an image sensor and an electronic device capable of performing imaging in which mixed color is reduced. Photoelectric conversion layers including photoelectric conversion units separated in units of pixels are stacked in two or more layers, the image sensor is configured to include a state in which light incident on one pixel in a first photoelectric conversion layer closer to an optical lens is received by the photoelectric conversion unit in a second photoelectric conversion layer distant from the optical lens, the image sensor includes a light-shielding layer configured to shield light transmitted through the first photoelectric conversion layer, between the first photoelectric conversion layer and the second photoelectric conversion layer, the light-shielding layer has an opening to transmit the light from the first photoelectric conversion layer to the second photoelectric conversion layer, and the openings are made to be asymmetric with respect to the pixel in the first photoelectric conversion layer. The present technology can be applied to an image sensor with a multi-layered structure.