‘Geumgang 1’ (Milyang307) is a high-yielding Tongil-type rice cultivar developed by the National Institute of Crop Science, RDA, in 2017 for the rice processing and baking industries. It was derived from a cross between ‘Dasan1’ and ‘Geumgangbyeo’. The cultivar heading date is on August 14 in the southern plain region of Korea and is classified as medium-late maturing. It has a culm length of 74 cm, 13 panicles per hill, 142 spikelets per panicle, a ripened grain ratio of 78.6%, and a 1,000-grain weight of 23.1 g. ‘Geumgang 1’ is resistant to leaf blast, bacterial blight (K1-K3a), and rice stripe virus but susceptible to brown planthopper. In regional adaptability tests (2015-2017) at three locations, it produced an average milled rice yield of 8.17 MT/ha, the highest recorded among Korean rice cultivars and was 23% higher than the yield of ‘Dasan’. With 19.0% amylose and flour properties similar to those of japonica rice, it is well suited as a wheat flour substitute for bakery products and is recommended for single-cropping plains in southern Korea (Registration No. 7686).