Action competence emerged in the 1980s in Denmark as a response to a demand for transformative and educational approaches fostering informed actions for real-world challenges, often with a focus on environmental sustainability. As action competence initially emerged in response to environmental concerns, its applicability to the social dimension of sustainability education requires deeper examination and understanding. This review synthesizes and analyzes studies on action competence in social sustainability, focusing on its conceptualization, integration, and practical applications. Its aim is to deepen our understanding of how action competence, as a critical tool, can foster more equitable, resilient, and sustainable social futures. A systematic online database search was conducted with ERIC, EBSCO, Scopus, Web of Science, as well as national databases in the Nordic countries. The inclusion criteria required the term “action competence” to appear in the title, abstract, or keywords, along with a focus on social sustainability. Studies that solely addressed environmental aspects were excluded. A total of 288 records were identified, of these 169 were unique, and 28 were included in the sample. The results highlight the critical role of action competence in equipping individuals and communities with the tools to foster sustainable and equitable societies.