Despite substantial inquiry into the euro-crisis’ constitutional implications and its impact on fundamental social and labour rights, the constitutional amendment of the social constitution remains an undocumented and unexplored area of the study of the euro-crisis. This thesis, bridging the fields of constitutional change and social constitutionalism, investigates the role of the eurocrisis in shaping constitutional amendment projects with regard to the social constitutions of sovereign debt states. It does so primarily through a comparative examination of the case-studies of Greece and Ireland, both places where projects to amend the social constitution, understood as involving social and labour rights, as well as fiscal constitutional arrangements, accelerated in the aftermath of the euro-crisis. I show how the euro-crisis influenced demands and projects to change the social constitution in these two sovereign debt states, albeit in different ways and to different degrees, with different constitutional actors and sites involved. I further consider the outcome for the social constitution of constitutionalizing European fiscal constraints through constitutional amendments. Examining the cases of Italy and Spain, I show that the constitutionalization of balanced budget rules as a response to the euro-crisis interacted with fundamental labour and social rights and challenged their protection. Overall, albeit to different degrees in different places, the euro-crisis has been an agent shaping the change of the social constitution, referring to amending and attempting to amend the social constitution by entrenching labour and social rights and reformulating the constitutional provisions protecting them, or to amending the fiscal constitution. Notwithstanding these outcomes of the euro-crisis, the latter has not been the only agent of change for the social constitution in the post-crisis years. I evidence that other crises, the need to adapt to a changing environment, and international socio-economic rights obligations have also animated discussions on constitutional change of European social constitutions.