The aim of this study is to empirically assess the effectiveness of green infrastructure (GI) in South Korea as a way to enhance flood resilience. The findings highlight the need to strengthen local resilience through spatially efficient expansion, hydrologically optimized design, and strategic allocation of GI, particularly considering flood vulnerability and interregional GI equity. By quantifying resilience costs and employing spatial analysis, this study advances both the theoretical understanding and the practical application of GI in flood-prone regions.