Archibald Alexander (April 17, 1772 – October 22, 1851) was an American Presbyterian theologian and professor at the Princeton Theological Seminary. He served for 9 years as the President of Hampden–Sydney College in Virginia and for 39 years as Princeton Theological Seminary's first professor from 1812 to 1851.
Archibald Alexander was born at South River, Rockbridge County, Virginia. He was raised under the tuition and ministry of Presbyterian minister William Graham (1745–1799), a man who had been trained in theology by John Witherspoon.
His grandfather, of Scottish descent, came from Ireland to Pennsylvania in 1736, and after a residence of two years removed to Virginia. William, father of Archibald, was a farmer and trader. His nephew was the American novelist William Alexander Caruthers (1802–1846).
On October 1, 1791, he was licensed to preach, ordained by the presbytery of Hanover on June 9, 1794, and for seven years was an itinerant pastor in Charlotte and Prince Edward counties.
By the time he was 21, Alexander was a preacher of the Presbyterian Church. He was appointed the president of Hampden–Sydney College, where he served from 1797 to 1806 and from there he was called to the Third Presbyterian Church of Philadelphia.
The Princeton Theological Seminary was established at Princeton, New Jersey in 1812 and Alexander was appointed its first professor, inaugurated on August 12, 1812. In 1824, he helped to found the Chi Phi Society along with Robert Baird and Charles Hodge. In 1843, he returned to Washington College to deliver an alumni address, which was one of his many publications.
Samuel Miller became the second professor at the seminary and for 37 years Alexander and Miller were considered together as pillars of the Presbyterian Church in maintaining its doctrines. Charles Hodge, a famous student and successor of Alexander, named his son Archibald Alexander Hodge after his mentor