Transformation is a desired process and outcome in both inter- and transdisciplinary discourses. While many semantic variations exist in different disciplines, in inter- and transdisciplinary knowledge fields, transformation is associated with non-linear multi-level, multi-dimensional, dynamic change required for overcoming the polycrisis humanity is facing. The transformative process can happen as part of, and as a result of, inter- and transdisciplinary inquiries, and the praxis and organization of knowledge production itself. The transformative outcome sought, within inter- and transdisciplinary processes, are profound changes in all scales and dimensions of life. The entry provides an overview on the etymology of the term transformation, its conceptualizations in different disciplines and specialized inter- and transdisciplinary knowledge fields, and the meanings and use of related terms in discourses on inter- and transdisciplinarity, including transformative science, paradigm, epistemology, research, learning and education.