The two-volume set CCIS 3024 + 3025 constitutes the refereed proceedings of the 27th International Conference on Engineering Applications of Neural Networks, EANN 2026, held in Chania, Crete, Greece, during July 16-19, 2026.The 51 full papers and 6 short papers presented in this volume were carefully reviewed and selected from 112 submissions. They are grouped into the following topics: LLMs, NLP, Knowledge and Code Intelligence; Vision, Multimodal Perception and Visual Sensing; Industrial, Engineering, Materials and Control AI; and Core ML, Trustworthy, Distributed and Edge AI.