This six-volume set LNCS 15986-15991 constitutes the proceedings of the 30th International Conference on Database Systems for Advanced Applications, DASFAA 2025, held in Singapore, during May 26&29, 2025. The 136 full papers presented in this book together with 89 short papers were carefully reviewed and selected from 731 submissions. They cover topics such as Part I- Machine Learning and Text. Part II- Emerging Application; NLP and Spatial-Temporal. Part III- Graph; Knowledge Graph. Part V- Recommendation and Security & Privacy. Part VI- Language Model; Industry Papers and Demo Papers.