A depth sensor includes a first pixel including a plurality of first photo transistors each receiving a first photo gate signal, a second pixel including a plurality of second photo transistors each receiving a second photo gate signal, a third pixel including a plurality of third photo transistors each receiving a third photo gate signal, a fourth pixel including a plurality of fourth photo transistors each receiving a fourth photo gate signal, and a photoelectric conversion element shared by first to fourth photo transistors of the plurality of first to fourth photo transistors.