Small businesses face multiple constraints on innovating that open innovation (OI) has potential to help overcome. The aim of this study is to examine the association between business group affiliation and the extent of OI engaged in by SMEs. Unlike independent SMEs, those that have affiliations might benefit from internal and also external networks to initiate partnerships to innovate. We analysed data collected from 711 French SMEs that engage in innovation to assess the association between business group affiliation and open innovation practices. We found that business group affiliation has no significant relationship with the degree of engagement in open innovation or with partnership openness. Nevertheless, we found that affiliation to an international group influences the geographical openness of SMEs’ innovation. These findings contribute to our understanding of open innovation among SMEs by acknowledging the geographical challenges of partnerships in open innovation.