This book is a contribution to the research community towards thinking and reflecting on what Responsible Machine Translation really means. It was conceived as an open dialogue across disciplines, from philosophy to law, with the ultimate goal of providing a wide spectrum of topics to reflect on. It covers aspects related to the development of Machine translation systems, as well as its use in different scenarios, and the societal impact that it may have. This text appeals to students and researchers in linguistics, translation, natural language processing, philosophy, and law as well as professionals working in these fields.