Startups are increasingly recognized as key participants in promoting “green” technologies that offer flexible and innovative solutions to pressing environmental problems. Unlike well-known corporations burdened with outdated systems, startups often see sustainability as a basic principle of operation, and not as a goal of compliance. They are implementing new technologies and new business models that effectively combat climate change, resource shortages, and environmental deterioration. This article examines startups’ strategic role in green innovation by analyzing their contribution to sustainable development, the ecosystems that enable them to grow, and the systemic challenges they face, such as limited access to environmental funding, fragmentation of legislation, and scaling barriers. Based on case studies, the fundamentals of international policy and innovation theory, the article highlights key factors contributing to the success of environmental startups, including investments aimed at specific goals, public–private partnerships, and innovative incubators focused on clean technology. The results show that “green” startups, supported by a concerted ecosystem of finance, regulation, and knowledge, could be the catalyst for the transition to a low-carbon economy. The document ends with strategic recommendations on the development of sustainable entrepreneurship, which emphasizes the need to create comprehensive support mechanisms, educational initiatives, and scalable financing models consistent with global climate change goals.