The 1274 full papers and 209 posters presented at the HCII 2019 conferences were carefully reviewed and selected from 5029 submissions. The papers cover the entire field of human-computer interaction, addressing major advances in knowledge and effective use of computers in a variety of applications areas. The papers in this volume are organized in the following topical sections: cognitive modeling, perception, emotion and interaction; human cognition and behavior in complex tasks and environments; brain-computer interfaces and electroencephalography; and augmented learning.