A depth pixel of an image sensor includes a depth sensing element configured to generate first charges that are photo-electrically converted from a light reflected from an object, a first floating diffusion node configured to receive the first charges from the depth sensing element, a second floating diffusion node configured to output second charges corresponding to a component of a reflection light where a component of an ambient light is cancelled, and an ambient light cancellation circuit configured to detect the ambient light to control a barrier level of a charge transfer path between the first floating diffusion node and the second floating diffusion node in response to the ambient light.