The famous engineer who invented the steam engine that powered the Industrial Revolution was James Watt. In the late 18th century, Watt improved upon earlier designs, making the steam engine more efficient and practical for various applications, such as in factories, mining, and transportation. His innovations contributed to the mechanization of labor, facilitating a transition from agrarian economies to industrialized societies. Watt's contributions were pivotal in propelling the Industrial Revolution and transforming economic structures across the globe.