The UN Decade of Education for Sustainable Development (2005-2014) aimed to take a socially critical and transformative approach to ESD through all forms of education. Unfortunately, it mainly focused on formal education and overlooked the informal education that is embedded in the community development process of tackling unsustainable problems in real life, especially from the perspectives of marginalized people. Besides the political and economic pressures that cause the gap, current theorizing in ESD, which draws from critical theory, focuses predominantly on formal education or schooling contexts. It offers little guidance on appropriate pedagogical practice in community development. Theorizing informal education for sustainable community development is needed to support the UN's Sustainable Development Goals by 2030, and decoloniality is a potential theoretical approach to this issue.