This research explores how small and medium-sized enterprises (SMEs) manage external stakeholders during open innovation (OI) processes. To date, extensive literature has explored OI within large organisations, however, there is limited understanding of how SMEs can strategically manage stakeholders during different stages of OI projects. Using a multi-grounded theory approach, 11 cases of SME OI projects were analysed across four regions within Europe. The findings reveal a wide range of primary and secondary stakeholders with varying levels of power and dependency were leveraged across the different stages of the OI projects. A model is presented which advances knowledge on how to map, analyse and manage stakeholders strategically in a SME-OI context. Our research helps advance theory on SME-OI stakeholder management processes and reveals appropriate stakeholder management strategies, which will assist SME managers in alleviating the SME-OI paradox.