This study examines the role of fintech adoption in mediating the relationship between perceived risk and business sustainability in Small and Medium Enterprises (SMEs) in Samosir Regency. Using a quantitative approach with data analyzed through Structural Equation Modeling (SEM), the study finds that fintech adoption significantly reduces the perceived risks faced by SME owners, which in turn contributes to long-term business sustainability. Digital technologies such as electronic payment systems, peer-to-peer lending platforms, crowdfunding, and mobile banking have proven to enhance operational efficiency, expand market reach, and improve financial transparency and control. These benefits help SMEs build resilience and competitiveness, especially in rural areas like Samosir where access to conventional financial services is limited. Despite the potential benefits, challenges such as limited technological knowledge, digital infrastructure gaps, regulatory uncertainty, and the lack of skilled human resources remain major barriers to effective fintech implementation. The study highlights that the role of government and stakeholders is vital in creating an enabling environment for fintech adoption. This includes policies that encourage innovation, facilitate access to digital infrastructure, provide education and training to increase digital literacy, and foster partnerships between SMEs and fintech service providers. Additionally, support from local communities and continuous awareness campaigns can further reduce resistance to change and increase trust in digital financial solutions. Overall, this research emphasizes that fintech adoption plays a crucial role in not only mitigating business risks but also supporting the long-term sustainability and growth of SMEs in the digital era.