AbstractIncreasing calls for transformation to address climate change and related challenges underscore the societal imperative to shift from mindsets that drive environmentally unsustainable and socially unjust processes to mindsets that enable urban sustainability transformations. However, it is not always clear what such mindsets comprise, if and how they can be shifted and under which conditions. Fragmented understandings of the concept of mindsets across disciplines and limited empirical analysis beyond Europe and North America have hindered progress in this field. To address these gaps, this article proposes a novel conceptual and analytical framework for identifying mindsets. The framework is applied to data collected from an exploratory survey involving over 150 participants from five Urban Labs in Argentina, Brazil and Mexico. Through cluster analysis, three distinct personas are identified: the Skeptical Activist, the Optimist Technocrat and the Bystander with Mixed Feelings. These are fictional characters that represent groups of individuals with defining mindsets, demographic characteristics, capacities, trust levels and network features. Results offer valuable insights into the emotions, beliefs, values, perceptions, attitudes and worldviews that guide the behavior of diverse stakeholders, from policymakers to often marginalized community groups, in urban climate governance. Despite its limitations, namely the relative homogeneity of our non-randomized sample, the article advances the understanding of the human dimension of climate change and its interlinkages with urban development goals. It also proposes social innovation strategies to trigger mindset shifts, foster climate action and accelerate urban sustainability transformations.