Purpose – This paper aims to introduce and investigate dialogic interaction as a key element of achieving a transition towards sustainability in people, organizations and society as a whole. Furthermore “sustainability competence” as a potential outcome of such interaction is to be introduced, referring to the capacities and qualities that people, and the organizations and communities of which they are part, need in order to address (un)sustainability. Design/methodology/approach – The argument of the paper is grounded conceptually in emergent thinking among scholars preoccupied with learning-based change and sustainability in organizations and communities. Empirically, the paper uses two case studies carried out by the authors to ground the argument in real efforts by communities to create a (more) sustainable way of living. Findings – The main results include: a post-normal understanding of sustainability highlighting uncertainty, complexity, normativity, controversy and indeterminacy; a framework facilitating dialogic interaction; and a number of key competences that appear conducive to both dialogic interaction and a transition to sustainability. Research limitations/implications – Although the two case studies are quite extensive and rigorous, the conceptual nature of the paper and the word limitation did not allow for a more detailed discussion of the methodology used in the case studies and the contexts in which the two case studies are located. Originality/value – The paper adopts a post-normal perspective of organizational transitions towards sustainability and focuses on dialogue and dialogic interaction as a key learning-based mechanism for facilitating such a transition. Furthermore the framework for dialogic interaction allows for a more holistic approach toward such a transition and the development of competences needed to accelerate its realization.