The Sustainable Development Goals (SDGs) have been heralded as a landmark achievement and a major opportunity for transformative and inclusive change towards sustainability. This promise, however, remains largely unverified. To help fill this gap, we examine how the SDGs have been taken up in the domestic politics of agri-food governance – a salient and contested policy area – in three South American countries: Brazil, Paraguay and Uruguay. Our empirical assessment is based on a scoping of the institutions set up for domestic SDG governance, document analysis of the first voluntary national reviews on the SDGs, and 63 key-informant interviews. The analysis shows that the ability of the SDGs to strengthen inclusiveness is largely shaped by domestic politics, pre-existing institutions and power relations, as well as the resources, capacities and prior experiences of civil society and subnational governments. In practice, the SDGs’ emphasis on inclusion does not necessarily mean that a wider range of perspectives are taken into account in domestic contexts. In Paraguay, the implementation of the SDGs so far mirrors the patterns of marginalization evident also in other policy processes. In Uruguay and Brazil, the SDGs have offered possibilities for at least drawing attention to a variety of perspectives by strengthening the already existing, fairly open political institutions in the case of Uruguay, and by opening up a space for contestation by civil society organizations and subnational governments in the case of Brazil. The SDGs may then be an opportunity for change, but there is also a risk that they become a justification for business as usual. Actors now employ metonymy as a tactic, cherry-picking preferred goals or targets as a sign of supposed adherence to the whole 2030 Agenda. Further research is needed with more ex-post analyses of the SDGs beyond the praising of their nominal transformative potential.