The majority of studies on open innovation have traditionally focused on large firms, ignoring the growing importance of collaboration for Small and Medium-sized Enterprises (SMEs) as a means of overcoming their inherent limitations. Despite their increasing reliance on collaboration, SMEs often face challenges to enter or develop networks due to their constrained resources. In this context, innovation clusters emerge as spaces with the potential to foster collaborative networks for SMEs, thereby enhancing their ability to assimilate external knowledge and generate new collaborative insights. Our research aims to examine the role of cluster governance as a catalyst for open innovation in SMEs. In our in-depth analysis of three prominent French innovation clusters, we compare four key knowledge-brokering practices and explore their impact on open innovation (OI) patterns. Our findings underscore the crucial role of cluster governance as an intermediary in enhancing SMEs' absorptive capacity and supporting their integration into collaborative networks. These practices hinge on the ability of cluster governance to forge robust cohesive links between diverse members, using different approaches to socialisation and/or formalisation.