A spool for a dual-bearing reel that allows accurate casting to be performed is provided. A spool includes a tubular bobbin trunk, and flange portions that project radially outward on both sides of the bobbin trunk. The flange portions include inner flange portions and outer flange portions. The inner flange portions are formed on both ends of the bobbin trunk, project radially outward, and are integrally formed with the bobbin trunk. The outer flange portions are formed on the outer peripheral surfaces of the inner flange portions, and radially project outward. The outer flange portions are outsert formed on the inner flange portions. The bobbin trunk is made from an aluminum alloy, and the outer flange portions are made from a magnesium alloy.