Ecovillages are collective projects that attempt to integrate sustainability principles into daily community life, while also striving to be demonstration projects for mainstream society. As spaces of experimentation, they can provide valuable insights into sustainability transformations. Through shared values and interpersonal connections, ecovillages possess collective identities, which provide a platform for enacting their ideals. However, many ecovillage residents question how to best enhance their role as models, resource centers, and pieces of a greater movement toward sustainability transformations, while simultaneously preserving their unique community and identity. In relation to the above, this paper addresses the questions: What can collective identity in ecovillage communities teach us about the objective and subjective dimensions of sustainability transformations? Furthermore, how can the perspective of collective identity highlight challenges for ecovillages for initiating sustainability transformations? Sustainability transformations encompass objective (behaviors) and subjective (values) dimensions; however, the interactions between these spheres deserve more scholarly attention. Using ethnographic data and in-depth interviews from three ecovillages in the United States, this paper reveals the value in collective identity for underscoring belonging and interpersonal relationships in sustainability transformations. Furthermore, the collective identity perspective exposes paradoxes and frictions between ecovillages and the societal structures and systems they are embedded within.