The inventive concepts provide a three-dimensional (3D) image sensor, based on structured light (SL), having a structure in which difficulty in a manufacturing process of a wiring layer is decreased and/or an area of a bottom pad of a capacitor is increased. The 3D image sensor includes: a pixel area including a photodiode in a semiconductor substrate and a gate group including a plurality of gates; a multiple wiring layer on an upper portion of the pixel area, the multiple wiring layer including at least two wiring layers; and a capacitor structure between a first wiring layer on a lowermost wiring layer of the multiple wiring layer and a second wiring layer on the first wiring layer, the capacitor structure including a bottom pad, a top pad, and a plurality of capacitors, wherein the bottom pad is connected to the first wiring layer.