This chapter focuses on competencies to be nurtured in Education for Sustainable Development (ESD) as transversal abilities (which we call “ESD competencies” in this chapter). ESD has emerged from an international educational movement that began spreading in the 2000s, aiming to train learners as future proactive builders of a sustainable society. In ESD, emphasis is placed on leading learners to recognize issues in contemporary society as their own and proactively work on these issues both by thinking globally and acting locally. To this end, ESD involves acquiring new values and transforming actions and behaviors that may lead to problem solving.