This two-volume set LNCS 11590 and 11591 constitutes the refereed proceedings of the 6th International Conference on Learning and Collaboration Technologies, LCT 2019, held as part of the 21st International Conference on Human-Computer Interaction, HCII 2019, in Orlando, FL, USA in July 2019. 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: designing and evaluating learning experiences; theoretical and pedagogical approaches in technology-enhanced learning; cognitive and psychological issues in learning; and technology in STEM education.