Interorganizational collaboration and the use of new digital technologies, such as artificial intelligence (AI), big data analytics, internet of things (IoT), or blockchain technology, are regarded as key enablers in implementing sustainability and circular economy‐oriented practices. While this is reflected in a few conceptual and case studies, statistical analyses on the topic are rare. No study so far has focused on collaboration, and digital technologies have only been studied in isolation. Therefore, the purpose of this study is to investigate the effect of interorganizational collaboration practices on a firm's circular economy practices and on outcomes (sustainability performance and economic performance), as well as the potentially facilitative role of new digital technologies on both. The research is based on a deductive approach, using a random sample of 112 Austrian manufacturing companies. The study employs partial least squares structural equation modeling (PLS‐SEM), features a multiple‐respondent design, and uses the dynamic capabilities view as a theoretical foundation. The study finds that interorganizational collaboration practices have a strong positive effect on the implementation of sustainability and CE practices, while the use of new digital technologies and general dynamic capabilities do not. The use of digital technologies positively affects only interorganizational collaboration, while general dynamic capabilities serve as an antecedent for both the use of digital technologies and interorganizational collaboration. Regarding the outcomes of CE implementation, the study finds a positive impact on firm‐level sustainability and economic performance. From a theoretical point of view, the study provides a new perspective on the prerequisites for successful CE implementation, highlights the importance of collaboration, and contextualizes the role of new digital technologies and dynamic capabilities. From a practical point of view, based on the positive outcomes found, the study supports arguments in favor of company engagement in CE activity. It also serves to motivate purposive digitization and systems thinking in order to create efficient CE collaboration networks.