Princeton Theological Seminary was established in 1812, the first Seminary founded by the General Assembly of the Presbyterian Church. The establishment of The Theological Seminary at Princeton marked a turning point in American theological education. Within the last quarter of the eighteenth century, all learning was of a piece and could be adequately taught and studied in the schools and colleges, nearly all of which were church initiated. General education was also the context for professional studies in divinity, medicine, and the law. In the first quarter of the nineteenth century, professional training became disengaged from the college curriculum, medical and law schools were established, and seventeen divinity schools and seminaries came into existence.

The plan to establish a theological seminary at Princeton was in the interests of advancing and extending the theological curriculum, to go beyond the liberal arts course by setting up a postgraduate, professional school in theology. The plan met with enthusiastic approval on the part of authorities at the College of New Jersey, later to become Princeton University, for they were coming to see that specialized training in theology required more attention than they could give.

With fewer than a dozen students, in 1812 Archibald Alexander was the first, and for one year the only, professor. He was joined the following year by a second professor, Samuel Miller, who came to Princeton from the pastorate of the Wall Street Church in New York.

To read the wording of the original “Design of the Seminary” is to perceive the early growth of the modern development in theological education in America, though the Princeton innovators were not at all thinking of breaking new ground except in the literal sense. They were prophetic enough, however, and among other things the “Design” noted that the purpose of the Seminary was

to unite in those who shall sustain the ministerial office, religion and literature; that piety of the heart, which is the fruit only of the renewing and sanctifying grace of God, with solid learning; believing that religion without learning, or learning without religion, in the ministers of the gospel, must ultimately prove injurious to the church.

The Seminary has been served by a remarkable succession of presidents. Francis Landey Patton (1902–1913) came to the Seminary after serving as president of Princeton University. J. Ross Stevenson (1914–1936) guided the Seminary through some turbulent years and expanded the institution’s vision and program. John A. Mackay (1936–1959) strengthened the faculty, enlarged the campus, and created a new ecumenical era for theological education. James I. McCord (1959–1983), whose presidency saw the institution of the first center of continuing education at a theological seminary, the establishment of full endowment for twenty-six faculty chairs, and the construction or renovation of major campus residences and academic facilities, gave leadership to both the national and world church through denominational and ecumenical councils. Thomas W. Gillespie (1983–2004) increased the size of the faculty, including the establishment of nine endowed chairs, and significantly lowered the student/faculty ratio.

Iain R. Torrance became the Seminary’s sixth president in 2004, having served as moderator of the General Assembly of the Church of Scotland, and dean of the Faculty of Arts and Divinity at the University of Aberdeen and professor of patristics and Christian ethics.

Since becoming Princeton's president, he has provided leadership in the areas of curriculum review, Seminary governance, and information technology, and has developed a new strategic plan for the institution.

Affiliated from the beginning with the Presbyterian Church and the wider Reformed tradition, Princeton Theological Seminary is today a denominational school with an ecumenical, interdenominational, and worldwide constituency. This is reflected in the faculty, in the curriculum of studies, and in the student body. There are currently more than 500 students enrolled in six degree programs.