This two-volume set constitutes the proceedings of the 13th International Conference on Universal Access in Human-Computer Interaction, UAHCI 2019, held as part of the 21st International Conference, HCI International 2019, which took place in Orlando, FL, USA, in July 2019. The total of 1274 papers and 209 posters included in the 35 HCII 2019 proceedings volumes was carefully reviewed and selected from 5029 submissions. UAHCI 2019 includes a total of 95 regular papers; they were organized in topical sections named: universal access theory, methods and tools; novel approaches to accessibility; universal access to learning and education; virtual and augmented reality in universal access; cognitive and learning disabilities; multimodal interaction; and assistive environments.