The global Covid-19 pandemic exposed the fragility of urban systems and underscored the need to recalibrate regulatory and institutional frameworks for an anticipated crisis-prone future. This article explores the notion of ‘adaptive law and governance’ as a lens through which city authorities can test and modify legal and governance responses to future urban crises. It compares the experiences of managing Covid-19 in the two biggest cities in the Netherlands (Amsterdam and Rotterdam) and in South Africa (Johannesburg and Cape Town). This comparison, between two sets of urban municipal governments functioning under different constitutional systems and in different socio-economic contexts, provides insights pertaining to how adaptive urban governance during the pandemic was constrained or enabled by the interaction between the regulatory and institutional frameworks for and political realities of urban autonomy and intergovernmental relations. The article demonstrates that cities that govern within a flexible and decentralised legal and governance system are better positioned to develop and implement responsive measures to address crises or uncertainty. To enhance resilience, legal systems should promote transparent, risk-responsive, and reflective local governance tools to enable agile, context- specific and decisive crisis responses that can be employed as a matter of course rather than exception.