This book constitutes the refereed proceedings of the Third Iberoamerican Conference on Applications and Usability of Interactive TV, jAUTI 2014, and the Third Workshop on Interactive Digital TV, WTVDI 2014, held as part of Webmedia 2014, João Pessoa, Brazil, in November 2014. The 10 revised full papers presented were carefully reviewed and selected from 26 submissions. The papers are organized in topical sections on IDTV overview; IDTV development tools; IDTV evaluation and testing; IDTV accessibility and usability.