Artificial intelligence and intelligent digital systems have become indispensible to many areas of modern life. This book presents the proceedings of the 1st International Conference on Novelties in Intelligent Digital Systems (NIDS2021), held in Athens, Greece, from 30 September to 1 October 2021. The conference took place as a virtual event due to COVID-19 restrictions. The NIDS conference lays special emphasis on the novelties of intelligent systems and on the interdisciplinary research which enables, supports, and enhances Artificial Intelligence (AI) in software development. It promotes high-quality research, creating a forum for the exploration of challenges and new advances in AI, and addresses experts, researchers and scholars in the fields of artificial and computational intelligence in systems and in computer sciences in general, enabling them to learn more about pertinent, strongly related and mutually complementary fields. The conference promotes an exchange of ideas, reinforcing and expanding the network of researchers, academics, and market representatives. The 30 accepted papers included here have each been reviewed rigorously by two or three reviewers through a double-blind process which reflects the commitment of the IIS academic community to make NIDS a top-flight, selective and high-quality conference. They are grouped in 6 sections, and cover the topics of Learning; Extended Reality; Data Mining and Machine Learning; Health and Environment; Brain Assessment and Reasoning; and Computer Vision Describing some very significant research and reflecting many interesting new ideas, the book will be of interest to all those working in the field.