Prefect of discipline (1863-1865), prefect of religion (1865-1866), and president (1872-1874) of the University of Notre Dame.

Auguste Lemonnier was born on April 11, 1839 in Anhuille, France. At the age of thirteen, he began his studies at the College of Precigne in Mans, France. Upon completion of these studies seven years later, he decided to study law, which he did in France for two years. In 1857, at the age of 28, he joined his brother at the Theological Seminary at Mans for a year. During this year, his uncle, Father Edward Sorin, induced him to come to America. Lemonnier first went to Rome to study theology at Roman College. He entered the Congregation of Holy Cross in October of 1860.

In February of 1861 he travelled to Notre Dame, where he completed his seminary studies. He was ordained a priest on November 4, 1863. His rise among the administration at Notre Dame was unprecedented. In November, 1863, shortly after his ordination, he was named Prefect of Discipline, an office he held until 1865 when he was named Prefect of Religion. He became vice-president of the university in 1866 and remained in that office for six years. In 1872 he was named president of the university, the position he held until his unexpected death on October 29, 1874 at the age of thirty-five.

During his tenure as both president and vice-president, Father Lemonnier sought to strengthen the university's curriculum by adding more courses and faculty in math and the sciences. He began the university library, which was originally housed in a building named for him (now the Architecture Library).