One Health recognizes the interconnectedness of human, animal, and plant health and the wider environment. Zoonotic diseases, those transmitted from animals to humans, and antimicrobial resistance pose significant threats. Combined, they erode agricultural productivity and global gross domestic product. A One Health approach, with its focus on integrated strategies, offers a cost-effective solution for promoting overall health and economic well-being.National governments play a crucial role in mobilizing domestic resources, but international partnerships are essential to maximize return on investment. Resource partners include multilateral development banks, philanthropic organizations, and private sector actors. This document provides profiles of key resource partners and investors and begins to map the financial ecosystem.