An image sensor including a light source configured to emit an optical signal to a target object, and a pixel array including a first pixel configured to generate pixel signals based on the optical signal reflected from the target object, the first pixel including a first photo gate group having at least two photo gates that are configured to receive first gate signals with a first phase difference from the optical signal in a time interval and a second photo gate group having at least two photo gates configured to receive second gate signals with a second phase difference from the optical signal in the time interval, may be provided.