<p>Intergenerational income mobility, a critical measure of social fairness and equal opportunity, has garnered significant attention due to its declining trend. Against the backdrop of the rapidly expanding digital economy, public data openness—an emerging governance tool—presents new opportunities for enhancing intergenerational income mobility. This paper constructs a theoretical framework to explore the mechanisms by which public data openness is related to changes in mobility, focusing on three key dimensions: diversification of economic opportunities, restructuring of social capital, and improving the governance environment. Empirical analysis, utilizing data from the China Family Panel Studies (CFPS) and the “China Open Data Index,” demonstrates that increased public data openness significantly associated with a weakening of the positive correlation between fathers’ and children’s incomes, thereby being related to an increase in mobility. Further investigation identifies three primary pathways through which public data openness is associated with this outcome: creating diversified economic opportunities, reshaping social capital, and optimizing the governance environment. Heterogeneity analysis reveals that the impact of public data openness on intergenerational income mobility varies significantly across regions, genders, and groups with differing perceptions of the role of networks in employment.</p>