The integration of 3D printing technology in construction presents a transformative approach to sustainable building practices. This paper examines the role of additive manufacturing in green buildings, focusing on its potential to minimize material waste, enhance energy efficiency, and reduce carbon footprints. The study explores the evolution of 3D printing in the construction sector, reviewing advancements in material science, automation, and design optimization. A comprehensive analysis of methodologies employed in 3D-printed construction is provided, supported by a case study illustrating its real-world applications. The findings highlight key benefits, including reduced construction time, cost savings, and improved structural integrity. However, technical challenges such as scalability, regulatory compliance, and material limitations are also discussed. Future research directions emphasize the integration of AI-driven automation and the development of eco-friendly printing materials to further advance sustainability in construction. The study concludes that while 3D printing is still evolving, its adoption in sustainable architecture can revolutionize the construction industry by fostering efficient and environmentally responsible practices.