This book constitutes the refereed proceedings of the Third International Conference on Distributed, Ambient, and Pervasive Interactions, DAPI 2015, held as part of the 17th International Conference on Human-Computer Interaction, HCII 2015, held in Los Angeles, CA, USA, in August 2015, jointly with 15 other thematically conferences. The total of 1462 papers and 246 posters presented at the HCII 2015 conferences were carefully reviewed and selected from 4843 submissions. These papers address the latest research and development efforts and highlight the human aspects of design and use of computing systems. The papers accepted for presentation thoroughly cover the entire field of human-computer interaction, addressing major advances in knowledge and effective use of computers in a variety of application areas. This volume contains papers addressing the following major topics: designing and developing intelligent environments; natural interaction; design and development of distributed, ambient and pervasive interactions; smart devices, objects and materials; location, motion and activity recognition; smart cities and communities; and humor in ambient intelligence.