An image sensor includes pixel regions separated by an isolation region and receiving incident light, color filters respectively disposed on a surface of the semiconductor substrate corresponding to the pixel regions, a cover insulating layer disposed on the surface of the semiconductor substrate and covering the color filters, first transparent electrodes disposed on the cover insulating layer and spaced apart to respectively overlap the color filters, an isolation pattern disposed on the cover insulating layer between the first transparent electrodes and having a trench spaced apart from the first transparent electrodes, a drain electrode disposed in the trench of the isolation pattern, and an organic photoelectric layer and a second transparent electrode sequentially disposed on the first transparent electrodes and the isolation pattern.