Image sensors may include a base substrate including a substrate layer, a buried insulation layer on the substrate layer, and a semiconductor layer on the buried insulation layer, a photo sensing device in the substrate layer, a buried impurity region spaced apart from the photo sensing device in an upper portion of the substrate layer, a transfer gate including a vertical gate extending through the semiconductor layer and the buried insulation layer and extending into an inner portion of the substrate layer, which is between the photo sensing device and the buried impurity region, a planar gate on the semiconductor layer, and a gate insulation layer between the substrate layer and the planar gate.