This 6-volume set LNCS 16535-16540 constitutes the proceedings of the 31st International Conference on Database Systems for Advanced Applications, DASFAA 2026, held in Jeju, South Korea, at April 27-30, 2026. The 228 full papers presented in this book were carefully reviewed and selected from 834 submissions. They cover topics such as:Search and RecommendationIndex and Storage SystemsGraph and Social NetworkMachine Learning for DatabaseCloud Data ManagementBio and Health InformaticsData-driven AIData Quality and CredibilityText and Data MiningData Mining and Knowledge DiscoverySecurity, Privacy and TrustInformation Extraction and SummarizationQuery Processing and OptimizationRDF and Knowledge GraphsDistributed Ledger and BlockchainIndustry PapersDemo Papers