The core challenge of this century is achieving a sustainable future amid pressing risks—climate change, biodiversity loss, social inequality, and economic instability. Governance and financial systems are currently misaligned with the objective of maintaining planetary boundaries and shared prosperity. It is contended that sustainable and green finance is pivotal for transitioning to a just and resilient economy. By leveraging financial capital, fiscal policy, and market design, green finance can accelerate low-carbon growth, protect ecosystems, and promote social inclusion. Drawing on multiple disciplines, we propose an integrated framework to mobilize resources, upgrade corporate governance, standardize ESG reporting, and support equitable tax policies. In each section of the paper, we examine a key dimension of finance's role, culminating in policy recommendations and a future research agenda. We conclude that reformed financial systems can internalize environmental costs, reduce systemic risks, and enable equitable development within planetary limits.