Abstract: The panel data of 41 prefecture-level cities in the Yangtze River Delta (YRD) from 2009—2020 are selected to examine the role of state-owned enterprises (SOEs) in the economic integration of the YRD. It is found that, in general, the development of state-owned enterprises not only has a direct impact on promoting the economic integration of the Yangtze River Delta, but also can promote the development of economic integration of the Yangtze River Delta by improving the level of regional innovation and industrial agglomeration. In the analysis of regional heterogeneity, the role of SOE development on the level of economic integration in Anhui Province is more significant than that in Jiangsu Province and Zhejiang Province.