The irreversible transition towards urban living entails complex challenges and vulnerabilities for citizens, civic authorities, and the management of global commons. Many cities remain beset by political, infrastructural, social, or economic fragility, with crisis arguably becoming an increasingly present condition of urban life. While acknowledging the intense vulnerabilities that cities can face, this article contends that innovative, flexible, and often ground-breaking policies, practices, and activities designed to manage and overcome fragility can emerge in cities beset by crisis. We argue that a deeper understanding of such practices and the knowledge emerging from contexts of urban crisis may offer important insights to support urban resilience and sustainable development. We outline a simple conceptual representation of the interrelationships between urban crisis and knowledge production, situate this in the context of literature on resilience, sustainability, and crisis, and present illustrative examples of real-world practices. In discussing these perspectives, we reflect on how we may better value, use, and exchange knowledge and practice in order to address current and future urban challenges.