The paper aims to explore how the synergy of financial technology (FinTech) with big data analytics (BDA) has dramatically reshaped the investment landscape, opening unprecedented pathways to re-imagine the future of sustainable finance in the post-COVID-19 world. This convergence has disrupted conventional financial norms by enabling cutting-edge tools for analyzing data, risk evaluation, and decision-making processes. The current study delves into the theoretical genesis, and basic tenets to delineate the complex interaction of this technological combination with decision-making rationality. This intricate fusion has triggered a profusion of innovative financial services catering to a wider stakeholder canvas and has significantly enhanced the financial community’s capacity for assessing the multi-faceted drivers of sustainable investment. With hope for the future of sustainable finance, these innovative solutions can help align investors’ capital with the natural and social systems that underpin their wealth. In essence, the fusion of FinTech and BDA, designed according to the theory of financial innovation, has laid the foundation for sustainable finance to step into the post-COVID-19 world. Driven by data-driven decision-making, innovation, and regulatory compliance, this confluence holds great promise in accelerating the transition toward a post-COVID-19 future that is more sustainable and resilient.