Skills-based volunteering programs sit at the intersection of corporate philanthropy and human resources (HR). These programs enable employees to volunteer their specialized skills to support non-profit organizations, while developing new skills along the way. While these programs are the fastest growing way that firms deliver on their corporate social responsibility strategy, the academic literature has all but ignored them. However, there is ample opportunity to build an understanding of skills-based volunteering from existing research that crosses the realms of employee volunteering and skills. This systematic literature review of 36 peer-reviewed articles forms the basis of this paper, where we provide a definition of skills-based volunteering, and offer a theoretical model to guide future HR research and practice on skills-based volunteering. •We shine a spotlight on the intersection of skills and volunteering.•We define skills-based volunteering to guide future research.•We map the terrain of the features and outcomes of skills-based volunteering.•Giving versus gaining skills lead to different, counterintuitive outcomes.•This practice is a clear way for HR to contribute to CSR strategy.