Ecuador's postneoliberal policy of Buen Vivir seeks to reduce social inequality and tackle complex disadvantages associated with gender, location, race-ethnicity and other social differences. The paper analyses governmental Buen Vivir policy thinking and institutional arrangements to explore how Buen Vivir frameworks approach the constitutional commitment to equality in diversity, in light of the global Sustainable Development Goal of "Leaving No-one Behind" (LNOB). In many respects Ecuador has undertaken an array of policy efforts to tackle complex inequalities, and highlights the challenges of LNOB. Situating state Buen Vivir in Ecuador's postcolonial institutionalisation , the paper examines how colonial-modern legacies of knowledge production and governance channel state Buen Vivir policy into the reproduction of exclusionary configurations of power and difference.British Academy Small grants (SG160723