<p>Holidays represent peak periods for population mobility. However, existing research has paid limited attention to the differences in mobility patterns across distinct holidays, and methodological approaches have often been confined to social network analysis. This study examines the spatial patterns and regional disparities of population mobility during China’s three major public holidays—the Spring Festival, May Day, and National Day—using Baidu migration big data from 2024. By integrating social network analysis with exploratory spatiotemporal data analysis, the study explores network structures, rank-size distributions, regional and provincial disparities, and local spatial dynamics across the three holiday periods. The key findings are as follows: (1) Population movement peaks during the Spring Festival, with May Day having the highest daily mobility and National Day falling in between. (2) The Spring Festival features both short- and long-distance inter-regional flows. May Day travel is mostly short-distance around major cities, while National Day involves more inter-regional movement to small and medium-sized cities. Intra-provincial travel dominates all three holidays. (3) Mobility patterns exhibit a southeast–northwest divide along the “Hu Line” and a diamond-shaped structure in the southeast. City mobility ranks follow the Rank-Size Rule but diverge to varying degrees from Zipf’s Law. (4) All holidays show strong spatial spillover and polarization effects. May Day has the most dynamic clustering, while Spring Festival patterns remain relatively stable. These findings provide valuable insights for informing targeted interventions and enhancing policy responsiveness to population mobility surges during major holidays.</p>