Deeptech startups are becoming vital contributors to sustainable entrepreneurship by transforming scientific research into solutions for major climate and social challenges. Built on advanced technologies such as AI, biotechnology, and clean energy systems, these ventures move beyond incremental innovation and offer high-impact pathways for systemic change. This chapter examines how deeptech startups embed sustainability within their missions and business models, and how supportive ecosystems, mission-aligned capital, and strong research partnerships help them transition from laboratory innovation to real-world impact. Through multiple case studies from Europe, the MENA region, and Southeast Asia, this chapter identifies key enablers and barriers shaping deeptech for promising ventures. It also introduces the deeptech for Good Canvas as a practical tool for founders and policymakers to align advanced technology development with environmental and social value creation. Overall, this chapter broadens the sustainable entrepreneurship discourse by demonstrating how deeptech can catalyze transformative, scalable sustainability outcomes.