This paper aims to highlight the role of solidarity funds in the development and support of national co-operative movements. Those are financial institutions specialized in supporting the start-up and growth of co-operatives. By adopting a case study approach, our analysis shows that solidarity funds emerged globally with similar objectives. Our international comparison focuses on Italy but includes France, the United Kingdom and Québec as a specific Canadian province with a French institutional environment. Despite their crucial importance, there is limited available research on this subject. To this end, our paper has policy implications; we need to consider establishing such institutions in countries where co-operatives are lagging behind as traditional financial institutions are often unable to finance co-operatives because of their property rights regime.