Alma mater (Latin: alma mater; pl.: almae matres) is an allegorical Latin phrase meaning 'nourishing mother'. It personifies a school that a person has attended or graduated from. The term is related to alumnus, literally meaning 'nursling', which describes a school graduate.

In its earliest usage, alma mater was an honorific title for various mother goddesses, especially Ceres or Cybele. Later, in Catholicism, it became a title for Mary, mother of Jesus. By the early 17th century, the nursing mother became an allegory for universities. Used by many schools in Europe and North America, it has special association with the University of Bologna, whose motto Alma Mater Studiorum ("nurturing mother of studies") emphasizes its role in originating the modern university.

Several university campuses in North America display artistic representations of alma mater, depicted as a robed woman wearing a laurel wreath crown. The earliest and most famous of these is the bronze Alma Mater statute at Columbia University, designed in 1901 by Daniel Chester French.

Although alma (nourishing) was a common epithet for Ceres, Cybele, Venus, and other mother goddesses, it was not frequently used in conjunction with mater in classical Latin. In the Oxford Latin Dictionary, the full phrase's origin is attributed to De rerum natura, in which Lucretius uses the term as an epithet for an unnamed earth goddess:

Denique caelesti sumus omnes semine oriundi
omnibus ille idem pater est, unde alma liquentis
umoris guttas mater cum terra recepit (2.991–993)

We are all sprung from that celestial seed,
all of us have same father, from whom earth,
the nourishing mother, receives drops of liquid moisture

After the fall of Rome, the term was used in Christian liturgy to describe Jesus' mother, Mary. "Alma Redemptoris Mater" is a well-known eleventh century antiphon devoted to Mary.

The earliest documented use of the term to refer to a university is in 1600, when the University of Cambridge printer, John Legate, began using an emblem for the university press. The first-known appearance of the device is in William Perkins', A Golden Chain, a book first printed by Legate in 1600. On the title-page, the Latin phrase Alma Mater Cantabrigia ("nourishing mother Cambridge") is inscribed on a pedestal bearing a lactating woman wearing a mural crown.