Biodiversity finance encompasses the range of financial mechanisms, policies, and investment models designed to protect, restore, and sustainably manage ecosystems. As global biodiversity declines at unprecedented rates, finance has become a central pillar of conservation and sustainability transitions. Biodiversity finance seeks to mobilize capital—from public funding, private investors, development banks, and blended finance instruments—to address ecological degradation, strengthen ecosystem resilience, and support community-based conservation. Its emergence is closely linked to the rise of ecosystem valuation, nature-based solutions, green finance, and climate adaptation frameworks, which aim to align economic systems with ecological sustainability. This encyclopedia entry critically examines the conceptual foundations of biodiversity finance, detailing the evolution of financial instruments such as green bonds, biodiversity credits, payments for ecosystem services (PES), conservation trust funds, and debt-for-nature swaps. It analyses the institutional architecture, governance challenges, monitoring requirements, and accountability frameworks required for credible biodiversity investments. Particular attention is given to Africa, where biodiversity represents both a global public good and a foundation for local livelihoods. The Rwanda Biodiversity Fund is presented as a detailed case study, illustrating innovative blended-finance approaches, community participation, and policy integration. The chapter also addresses core debates, including risks of commodifying nature, greenwashing, inequitable benefit-sharing, and the structural power asymmetries embedded in global conservation finance. Ethical and political considerations surrounding Indigenous rights, land tenure, and ecological justice are explored. Finally, the chapter outlines emerging future directions such as AI-driven biodiversity auditing, digital environmental asset markets, and regenerative investment models. Through a comprehensive analytical lens, it argues that biodiversity finance can contribute to socio-ecological resilience—but only when grounded in robust governance, equity principles, and ecological integrity.