Covid-19 and pandemics more generally highlight the challenges of governing public health from a wide range of perspectives. One key issue is that of multilevel governance and where and how powers should be allocated. This paper considers whether localised or centralised approaches are more appropriate in the context of governing disease outbreaks and in light of the broad concept of subsidiarity. This issue comes clearly in to focus in the context of epidemiological units where internal jurisdictional boundaries exist, as in the case of the island of Ireland. The paper will firstly outline the theoretical aspects of subsidiarity, including democratic considerations, effectiveness, externalities and coherency. It will then consider the nature of Covid-19 and the potential policy approaches that can be adopted, taking into account also the precautionary principle. The final substantive section of the paper will provide a preliminary evaluation of the approaches across the island of Ireland and consider how these could be improved in light of subsidiarity. Overall, much greater coherency and also coordination of approaches will be required if effectiveness is to be ensured. On balance subsidiarity would appear to demand some centralisation of approaches.