The integration of Industry 4.0 and sustainability has paved the way for transformative practices in manufacturing, leading to the development of smart factories with a focus on greener futures. This chapter explores the synergy of Industry 4.0 technologies and sustainability. It emphasizes the collective potential of the two paradigms for the optimization of production processes, energy efficiency, and waste management. The integration of Industry 4.0 technologies including artificial intelligence, internet of things, big data analytics, robotics, and automation is playing a pivotal role in transforming the manufacturing processes and enabling the environmentally sustainable operations. The development of smart factories aligning with the sustainability goals has led to eco-efficiency and greener futures. In this chapter, responsible sourcing, circular economy, and energy management have been investigated along with the implementation opportunities and challenges.