Samuel Colt (/koʊlt/; July 19, 1814 – January 10, 1862) was an American inventor, industrialist, and businessman who established Colt's Patent Fire-Arms Manufacturing Company and made the mass production of revolvers commercially viable.

Colt's first two business ventures were producing firearms in Paterson, New Jersey, and making underwater mines. His business expanded rapidly after 1847, when the Texas Rangers ordered 1,000 revolvers during the American war with Mexico. During the American Civil War, his factory in Hartford supplied firearms both to the North and the South. Later, his firearms were used widely during the settling of the western frontier. When Colt died in 1862, he was one of the wealthiest men in the United States.

Colt's manufacturing methods were at the forefront of the Industrial Revolution. His use of interchangeable parts helped him become one of the first to make efficient use of the assembly line manufacturing process. Moreover, his innovative use of art, celebrity endorsements, and corporate gifts to promote his wares made him a pioneer in advertising, product placement, and mass marketing.

Samuel Colt was born in Hartford, Connecticut the son of Christopher Colt (1780–1850), a farmer who had moved his family to the city after he became a businessman, and Sarah (née Caldwell). His maternal grandfather, Major John Caldwell, had been an officer in the Continental Army; one of Colt's earliest possessions was John's flintlock pistol. Colt's mother died from tuberculosis when Colt was six years old, and his father married Olivia Sargeant two years later. Colt had three sisters, one of whom died during her childhood. His oldest sister, Margaret, died of tuberculosis at age 19, and the other, Sarah Ann, later died by suicide. One brother, James, became a lawyer; another, Christopher, was a textile merchant. A third brother, John C. Colt, a man of many occupations, was convicted of an 1841 murder and died by suicide on the day he was to be executed.

At age 11, Colt was indentured to a farmer in Glastonbury, where he did chores and attended school. Here he was introduced to the Compendium of Knowledge, a scientific encyclopedia that he preferred to read rather than his Bible studies. Its articles about Robert Fulton and gunpowder motivated Colt throughout his life. He discovered that other inventors in the Compendium had accomplished feats that were once deemed impossible, and he wanted to do the same. Later, after hearing soldiers talk about the success of the double-barreled rifle and the impossibility of a gun that could shoot five or six times without reloading, Colt decided that he would create the "impossible gun".

In 1829, at the age of 15, Colt began working in his father's textile plant in Ware, Massachusetts, where he had access to tools, materials, and the factory workers' expertise. Using what he learned from the Compendium, Samuel built a homemade galvanic cell, and advertised that as a Fourth of July event that year that he would explode a raft on Ware Pond using underwater explosives; although the raft was missed, the explosion was still impressive. Sent to boarding school, he amused his classmates with pyrotechnics. In 1830, a July 4 accident caused a fire that ended his schooling, and his father sent him away to learn the seaman's trade. On a voyage to Calcutta aboard the brig Corvo, Colt had the idea for a type of revolver, inspired by capstans and windlasses, which have a ratchet-and-pawl mechanism he would later say gave him the idea for his revolver designs. On the Corvo, Colt made a wooden model of a pepperbox revolver out of scrap wood. It differed from other pepperbox revolvers at the time in that it allowed the shooter to rotate the cylinder by the action of cocking the hammer, with an attached pawl turning the cylinder, which was then locked firmly in alignment with one of the barrels by a bolt, a great improvement over the earlier designs, which required rotating the barrels by hand and hoping for proper indexing and alignment.

When Colt returned to the United States in 1832, he resumed working for his father, who financed the production of two guns, a rifle and a pistol. The first completed pistol exploded when it was fired, but the rifle performed well. His father would not finance any further development, so Samuel needed to find a way to pay for the development of his ideas. He had learned about nitrous oxide (laughing gas) from the chemist at his father's textile plant, so he took a portable laboratory on tour and earned a living performing laughing gas demonstrations across the United States and Canada, calling himself as "the Celebrated Dr. Colt of New-York, London and Calcutta". Colt thought of himself as a man of science and believed if he could enlighten people about a new idea like nitrous oxide, he could in turn make people more receptive to his new idea concerning a revolver. He started his lectures on street corners and soon worked his way up to lecture halls and museums. As ticket sales declined, Colt realized that "serious" museum lectures were not what the people wanted to pay for; it was dramatic stories of salvation and redemption the public craved. While visiting his brother John in Cincinnati, he partnered with sculptor Hiram Powers for his demonstrations with a theme based on The Divine Comedy. Powers made detailed wax sculptures and paintings based on demons, centaurs, and mummies from Dante's work. Colt constructed fireworks for the finale of the show, which was a success. According to Colt historian Robert Lawrence Wilson, the "lectures launched Colt's celebrated career as a pioneer Madison Avenue-style pitchman". His public speaking skills were so prized that he was thought to be a doctor and was pressed into service to cure an apparent cholera epidemic aboard a riverboat by giving stricken passengers a dose of nitrous oxide.

Having saved some money and still wanting to be considered an inventor as opposed to a "medicine man", Colt made arrangements to begin building guns using proper gunsmiths from Baltimore, Maryland. He abandoned the idea of a multiple-barreled revolver and opted for a single fixed-barrel design with a rotating cylinder. The action of the hammer would align the cylinder bores with the single barrel. He sought the counsel of a friend of his father, Henry Leavitt Ellsworth, who loaned him $300 and advised him to perfect his prototype before applying for a patent. Colt hired a gunsmith by the name of John Pearson to build his revolver. Over the next few years, Colt and Pearson argued about money, but the design improved and by 1835 Colt was ready to apply for his U.S. patent. Ellsworth was now the superintendent of the U.S. Patent Office and advised Colt to file for foreign patents first, as a prior U.S. patent would keep Colt from filing a patent in the United Kingdom. In August 1835, Colt left for England and France to secure his foreign patents.