A self-cleaning screen includes a rotatable drum made of mesh material and an inlet pipe extending through a front end of the drum. A flotation structure supports the drum with the inlet pipe and the lower part of the drum submerged during use. A cleaning spray system located within the drum receives cleaning water through a hollow shaft supporting a rear end of the drum. Spray nozzles located within an upper part of the drum above the water level direct the cleaning water radially outward to dislodge debris from the screen. The front end of the drum includes an annular ring and a rubber seal extending radially inwardly from the annular ring to engage the inlet pipe. A drive belt extends around the annular ring to rotate the drum. A plurality of rollers engage an outer surface of the annular ring to support the drum for rotation about a horizontal axis.