Alexis I. du Pont (1816-1857) was proprieter of his family business, E.I. du Pont de Nemours & Company, which began in the manufacture of gunpowder in 1802. He was the youngest child of Eleuthère Irénée du Pont (1771-1834), the founder of the DuPont Company. He was educated at Mt. Airy College in Germantown, Pennsylvania, and at the New Haven Gymnasium from 1829 to 1831, where his nephew, James Eleuthère Bidermann (1790-1865), was a classmate. In 1831, he entered the University of Pennsylvania, where he completed his scientific studies in 1835, but did not earn a degree.

In 1836, he married Joanna Maria Smith (1815-1876), the daughter of Francis Gurney Smith (1784–1873) of Philadelphia and a sister of Dr. Thomas Mackie Smith (1809-1852), who had married Alexis I. du Pont's sister Eleuthera du Pont Smith (1806-1876). Alexis I. du Pont and Joanna Maria Smith du Pont had eight children.

Alexis I. du Pont became a partner in E.I. du Pont de Nemours & Company in 1837 and continued as such until his death on August 23rd, having been fatally injured in an explosion of the powder mills on the preceding day.