This study investigates the relationship between digital financial inclusion and water pollution using panel data from 31 Chinese regions (2014–2023). According to the results, there is a significant inverted U-shaped relationship between digital financial inclusion and pollution. After achieving a developmental threshold through effective resource allocation and the empowerment of green technology, pollution is reduced. The effect is less pronounced in central and western China, where outdated industrial structures and the “pollution haven” effect of foreign direct investment are more prevalent, but it is more pronounced in eastern China due to contemporary digital infrastructure and industrial upgrading. Economic growth mechanistically exhibits partial mediation, worsening early-stage pollution while permitting cleanup at a later time. Expanding digital infrastructure in central and western China and enhancing digital financial inclusion-green industry integration in the east are proposed as two regionally specific priorities to leverage synergistic digital-economic-environmental governance for sustainable water quality management.