As global demands for cleaner technologies and resource-efficient systems intensify, bio-based nanotechnology has emerged as a promising frontier for addressing environmental and energy challenges. However, despite its potential, significant barriers remain that hinder its widespread adoption and implementation. This chapter critically examines these challenges, including the complex synthesis and scalability of bio-based nanomaterials, their limited stability and performance under real-world conditions, and persistent concerns regarding toxicity, environmental fate, and long-term safety. It also highlights economic and regulatory hurdles, such as high production costs, the absence of standardized protocols, and insufficient policy frameworks that slow commercialization. The chapter emphasizes the importance of integrating sustainability and life cycle thinking, with discussions on biodegradability, recyclability, and the role of bio-based nanomaterials in promoting a circular economy. Looking forward, the chapter explores transformative opportunities such as the development of smart and multifunctional nanomaterials, integration with artificial intelligence (AI) and Internet of Things (IoT) technologies for real-time environmental and energy monitoring, and novel applications in hydrogen, solar, and bioenergy systems. Ultimately, the chapter calls for interdisciplinary collaboration, innovation in green chemistry, and forward-looking policy initiatives to fully realize the potential of bio-based nanotechnology in driving sustainable development.