This book constitutes the proceedings of the 6th International Conference on Applied Intelligence and Informatics, AII 2026, held in London, UK, during October 21-23, 2026.The 31 full papers included in these proceedings were carefully reviewed and selected from 119 submissions. They were organized in the following topical sections: Emerging Applications of AI and Informatics; Application of AI and Informatics in Healthcare; Application of AI and Informatics in Pattern Recognition; and Application of AI and Informatics in Network, Security and Analytics.