This book is a collection of research results in a wide range of topics related to human-robot interaction, both physical and cognitive, including theories, methodologies, technologies, and empirical and experimental studies. The works contained in the book have been presented at the 14th International Workshop on Human-Friendly Robotics (HFR 2021), organized by the University of Bologna (Bologna, Italy, October 28-29, 2021), and they describe the most original achievements in the field of human-robot interaction coming from the ideas of young researchers. The intended readership of the book is any researcher in the field of robotics interested to research problems related to human-robot coexistence, like robot interaction control, robot learning, and human-robot co-working.