A depth sensing apparatus and method for acquiring a depth image of a target object may calculate a difference voltage between a first floating diffusion node and a second floating diffusion node, based on a voltage of a photodiode stored in the first floating diffusion node in a first phase interval and a voltage of the photodiode stored in the second floating diffusion node in a second phase interval, using a sub-integration period, may feed back the difference voltage to one of the first floating diffusion node and the second floating diffusion node, and may calculate a depth value of a pixel based on difference voltages accumulated during an integration period including sub-integration periods.