Abstract: FDI is an important tool for utilizing high-quality foreign investment. The strategy of coordinated regional development is one of the "five coordination" put forward at the Third Plenary Session of the Sixteenth Central Committee of the Communist Party of China (CPC). Therefore, it is particularly important to clarify the relationship between the two in the context of the country's efforts to promote high-quality development. The evaluation index system of regional coordinated development was constructed in this paper. The entropy method was used to measure the specific values. Based on the panel data of 11 provinces and municipalities in the Yangtze River Economic Belt from 1990 to 2022, the spatial autocorrelation between FDI and regional coordinated development was examined by using the whole-area Moran index. The spatial linkage model with decomposable effect values was utilized to explore the existence of FDI and regional coordinated development. The spatial equation model with decomposable effect values was used to investigate the interaction and spatial spillover effects between FDI and regional coordinated development. The results showed that: (1) FDI and regional coordinated development promoted each other. (2) There was a significant positive spatial spillover effect between FDI and regional coordinated development. This paper had important theoretical value and practical significance for the utilization of high-quality foreign investment in the context of high-level opening-up and the in-depth promotion of regional coordinated development strategy.