The European Social Catalyst Fund (ESCF) is a new initiative designed to have significant impact on some of Europe’s most pressing social challenges. The objective of the ESCF is to bring together public and private resources to improve social services to enable people who need support to live as valued and participating members of their communities. The ESCF will provide financial and capacity building support to develop plans to scale proven social service innovations. It is anticipated that these plans will provide details of how public and private resources (philanthropy and/or social investment) can be brought together in a range of collaborations that focus on the role that philanthropy and social finance can play in working with the public sector to help re-focus public spending in a more effective direction in the interest of European citizens. It is intended that during the project a further phase will be designed, based on learning obtained, which will include a focus on supporting implementation of plans to scale proven social service innovations. The ESCF has been established and co-funded by the European Union’s Horizon 2020 Research and Innovation Programme, Genio (Ireland), the Robert Bosch Stiftung (Germany) and the King Baudouin Foundation (Belgium). It will award planning grants across a range of priority social challenge areas within, or across, European Union Member States. The purpose of the grants is to support the development of detailed implementation plans aimed at reducing, or overcoming, social challenges. Innovations will be identified through a pan-European call and all eligible applications will be evaluated against published criteria. Preference will be given to innovations that have the most robust evidence of success and that aim to reach the most significant scale. Each selected application will receive a planning grant of up to €100,000 along with capacity building support. A minimum of €600,000 will be allocated to support at least 6 plans.