This paper provides preliminary insights into a study of the emerging practices of public librarians working proactively for sustainable societal transformation. Theoretically, the paper builds on ideas of social entrepreneurship and inside activism to understand the librarians as change agents and intermediary actors and their work as social innovation. Empirically, the paper builds on a case study of a Danish library system, Ballerup public libraries, and the emerging practices of the librarians working with the UN 2030 sustainability agenda and the Sustainable Development Goals (SDGs). Moreover, the paper focuses on how these social innovations have been sustained in practice through the national inter-organizational network DB2030. As part of this network, the libraries/librarians provide information about and disseminate the SDGs. Moreover, the libraries/librarians actively work to solve the problems by engaging the civic society to act on them. What is distinctive about this case is how the public libraries are framed as part of the solution. As a result of the work of the library/librarians and the DB2030 network in the 2021 Danish governmental Action Plan for the SDGs, public libraries are mentioned as anchors for citizen engagement in the SDGs. Thus, this case exemplifies a re-politicization of cultural politics. Using the idea of utopia as a methodology for working with social innovation, this paper argues that the proactive work of the librarians represents emerging practices, pointing to future scenarios where cultural institutions play a more active role in solving collective problems and effecting a sustainable societal transformation.