Book excerpt: This set of 35 volumes constitutes the proceedings of all of the conferences affiliated with HCI International 2019, which was held in Orlando, Florida, USA, in July 2019. The 1274 papers and 209 posters presented were carefully reviewed and selected from 5029 submissions. The respective focus of the 18 conference is as follows: Human-Computer Interaction; Human Interface and the Management of Information; Engineering Psychology and Cognitive Ergonomics; Universal Access in Human-Computer Interation; Virtual, Augmented and Mixed Reality; Cross-Cultural Design; Social Computing and Social Media; Augmented Cognition; Digital Human Modeling and Applications in Health, Safety, Ergonomics and Risk Management; Design, User Experience, and Usability; Distributed, Ambient and Pervasive Interactions; HCI in Business, Government and Organizations; Learning and Collaboration Technologies; Human Aspects of IT for the Aged Population; HCI for Cybersecurity, Privacy and Trust; HCI in Games, HCI in Mobility, Transport and Automotive Systems; and Adaptive Instructional Systems. The set therefore provides readers with a comprehensive overview of ongoing research and development within the broad field of Human-Computer Interaction.