The disclosure discloses a water tank and a cleaning robot, the water tank is applied to the cleaning robot, internally provided with a water storage cavity. The water tank has a splicing side, the splicing side is provided with an accommodating area recessed towards the inside of the water tank, the splicing side of the water tank is configured to splice with the body of the cleaning robot, and the accommodating area is configured to accommodate part of the structural parts of the body of the cleaning robot.