Samuel Slater (June 9, 1768 – April 21, 1835) was an early English-American industrialist known as the "Father of the American Industrial Revolution", a phrase coined by Andrew Jackson, and the "Father of the American Factory System". In the United Kingdom, he was called "Slater the Traitor" and "Sam the Slate" because he brought British textile technology to the United States, modifying it for American use. He memorized the textile factory machinery designs as an apprentice to a pioneer in the British industry before migrating to the U.S. at the age of 21.

Slater designed the first textile mill in the U.S. He later went into business for himself, developing a family business with his sons. He eventually owned 13 spinning mills and developed tenant farms and company towns around them. One of these towns was Slatersville, Rhode Island.

Slater was born to William and Elizabeth Slater on June 9, 1768, in Belper, Derbyshire, England. He was the fifth son in a farming family of eight children. He received a basic education, perhaps at a school run by Thomas Jackson. At age ten, he began work at the cotton mill opened that year by Jedediah Strutt using the water frame pioneered by Richard Arkwright at nearby Cromford Mill. In 1782, his father died, and his family indentured Samuel as an apprentice to Strutt. Slater was well trained by Strutt and, by age 21, he had gained a thorough knowledge of the organization and practice of cotton spinning.

He learned of the American interest in developing similar machines, and he was also aware of British law against exporting the designs. He memorized as much as he could, and departed for New York City in 1789. Some people of Belper called him "Slater the Traitor", as they considered his move a betrayal of the town where many earned their living at Strutt's mills.

In 1789, Rhode Island–based industrialist Moses Brown moved to Pawtucket, Rhode Island, to operate a mill in partnership with his son-in-law William Almy and cousin Smith-Brown. Almy & Brown, as the company was to be called, was housed in a former fulling mill near the Pawtucket Falls of the Blackstone River. They planned to manufacture cloth for sale, with yarn to be spun on spinning wheels, jennies, and frames, using water power.

In August 1789, they acquired a 32-spindle frame "after the Arkwright pattern" but could not operate it. At this point, Slater wrote to them, offering his services. Slater realized that nothing could be done with the machinery as it stood and convinced Brown of his knowledge. He promised: "If I do not make a good yarn, as they do in England, I will have nothing for my services but will throw the whole of what I have attempted over the bridge."

In 1790, he signed a contract with Brown to replicate the British designs. Their deal provided Slater with the funds to build the water frames and associated machinery, with a half share in their capital value and the profits derived from them. Slater found no mechanics in the U.S. when he arrived and had great difficulty finding someone to build the machinery. Eventually, he located Oziel Wilkinson and his son, David, to produce iron castings and forgings for the machinery. According to David Wilkinson: "all the turning of the iron for the cotton machinery built by Mr. Slater was done with hand chisels or tools in lathes turned by cranks with hand power".

By 1791, Slater had some of the equipment operating, despite shortages of tools and skilled mechanics. He was able to single-handedly construct from memory the water-powered spinning machinery. By December, the shop was operational with ten to twelve workers. In 1793, Slater and Brown opened their first factory in Pawtucket.