This article examines the potential of Universal Basic Income (UBI) to support a just eco-social transition by enabling the emergence of new emancipatory social imaginaries and practices. Against the backdrop of ecological breakdown and deepening precarity under global capitalism, it explores how UBI may function as a democratic tool for socio-ecological transformation. The argument centers on recent contributions that advocate for a UBI-centered, post-productivist agenda capable of delinking subsistence from wage labor as a means to achieve desirable eco-social outcomes. The article highlights ways in which UBI can contribute to this transition. The argument evolves by contrasting UBI with other eco-social policies proposed for such purposes, such as Universal Basic Services (UBS) and a conditional Ecological Participation Income (EPI). While UBS has been advanced as a rival alternative to UBI, we argue that it is in fact fully compatible with—and may be fruitfully combined with—a UBI. While institutional pluralism should be welcomed, we argue that an EPI-based pathway toward an emancipatory, eco-social welfare state may easily become self-defeating by reinforcing and multiplying objectionable forms of administrative complexity and welfare paternalism. From the post-productivist perspective that unite all these proposals, we contend that a fully unconditional UBI takes precedence as the default option for pursuing social welfare within planetary boundaries. However, the eco-social potential of UBI depends on its integration into broader institutional infrastructures and social strategies for nurturing cultural narratives that redefine the meaning of work, participation and sustainable welfare. Ultimately, the article positions UBI policy not as a standalone solution or universal blueprint but as a potential enabler and a source of inspiration for systemic emancipatory change—opening space for personal autonomy, collective empowerment, and eco-social experimentation. It contributes to sociological debates on degrowth/postgrowth, climate justice, and the transformative power of social imaginaries in shaping sustainable and inclusive futures.