Alasdair Chalmers MacIntyre was born 12 January 1929 in Glasgow, Scotland, to John and Emily (Chalmers) MacIntyre. He was educated at the University of London and Oxford University and began his teaching career in Great Britain at Manchester University in 1951. He also taught at Leeds University, Essex University and Oxford University. In 1969, he came to the United States and took a position as professor of the history of ideas at Brandeis University. In 1972, he was appointed dean of the College of Liberal Arts and professor of philosophy at Boston University. In 1980, he was awarded the Henry Luce Professor at Wellesley College; in 1982, the W. Alton Jones Professor at Vanderbilt University; and in 1984, he was president of the Eastern Division of the American Philosophy Association. He took a position as professor of philosophy at the University of Notre Dame in 1985. He went to Vanderbilt University in Nashville, Tennessee, later in 1985. He was a professor of philosophy there until 1988, when he became a visiting scholar at the Whitney Humanities Centre at Yale University (1988–1989). He then accepted the position of McMahon-Hank Professor of Philosophy at Notre Dame (1989–1994). From 1995 to 1997, he was the Arts & Sciences Professor of Philosophy at Duke University. From 2000 to 2008, he has been the Rev. John A. O’Brien Senior Research Professor and the Permanent Senior Research Fellow at the University of Notre Dame. He is also professor emeritus at Duke University. In April 2005, he was elected to the American Philosophical Society.

Alasdair MacIntyre believes the history of philosophy is profoundly relevant to contemporary life and thought, and the philosophical systems of such figures as Aristotle and Aquinas could and ought to be used as viewpoints from which contemporary thought itself can be criticized. For MacIntyre, the history of philosophy is not necessarily a history of progress in which our grasp of truth is improving. Rather, he argues earlier traditions within philosophy are, in many respects, far more intellectually adequate than contemporary systems of thought, and people ought to, in some significant ways, return to these earlier systems for first principles. In this respect, he may be referred to as a philosophical conservative.

Alasdair MacIntyre has written thirty-three books in philosophy, religion and theology since his first book, Marxism: An Interpretation, appeared in 1953. Other notable publications include the influential triumvirate of recent works: After Virtue: A Study in Moral Theory (1981); Whose Justice? Which Rationality? (1988); and Three Rival Versions of Moral Enquiry: Encyclopaedia, Genealogy, and Tradition (1990). He received a Metcalf Prize in 1974 and a DHA from Swarthmore College in 1983. Other honorary degrees include: DLit, Queens University of Belfast (1988); DUE, University of Essex (1990); DLit, Williams College (1993); and DHL for the New School for Social Research (1996).