Crises, such as natural disasters, terrorist events, economic breakdowns, or disease outbreaks, pose fundamental challenges to governments. An important question is how governments can respond to and deal with crises, not only in an effective way, but also in a legitimate way. The legitimacy of crisis governance has received significant attention in the wake of the COVID-19 pandemic, with government responses that impacted virtually all citizens worldwide and that sometimes led to protests and other challenges to the legitimacy of measures and the authorities passing them. At the same time, the pandemic demanded coordinated action from governments at all levels, requiring a legitimate crisis response sensitive to the needs of federalism, decentralization, supranational authorities and other multilevel governance (MLG) institutions and processes. Despite this increasing scholarly attention, the role that MLG has played in government responses to the pandemic remains uncertain as the literature remains fragmented. Additionally, there is a need for a conceptualization of legitimate crisis governance to better understand these responses and contribute to future effective crisis response. In this three-part deliverable, we first synthesize the literature on the effects of MLG on governments’ policy responses to COVID-19 through a systematic literature review. The systematic literature review shows that while current scholarship reveals much about national, subnational and local responses, it remains limited by a narrow set of research methods, comparisons across cases that are solely of one or another MLG-type, and a lack of specificity regarding the government response studied. The second part of the deliverable develops a conceptual framework for analyzing and assessing the legitimacy of crisis governance and develops a set of expectations that can guide empirical research into the legitimacy of crisis governance. Taking these two perspectives as a starting point, the third part of the deliverable proposes a mixed methods research design for testing the framework to better understand the effects of multilevel governance systems on crisis governance responses and citizens’ perceptions of their legitimacy.