The world is facing complex global societal challenges including accelerating climate change, a pandemic, rising social inequalities also in well-functioning welfare states, cultural and linguistic diversity, and a renewed call for racial justice. Developmental psychology can make strong contributions to address these and other global challenges because developmental psychologists have the necessary theoretical, methodological, and empirical knowledge. This paper discusses (1) the usefulness of a relational developmental theoretical perspective, (2) implications for study designs and methodologies, (3) which competences should ideally be fostered early on to prepare adults to cope with global societal challenges that need high levels of future-oriented, cooperative, and collective efforts, and (4) the implementation gap between what is known in developmental psychology and what is done in educational settings. Overall, this paper is a plea for strong voices from developmental psychology to help solve current and future global societal challenges.