Saint Monica High School traces its origin to the turn of the century when the Sisters of the Holy Names of Jesus and Mary, at the request of Bishop Montgomery, first opened a small elementary school in 1899.

In 1901, to meet the need for more facilities and a potential high school, the sisters erected the "Academy of the Holy Names" which stood at the corner of Third and Arizona Streets.  The Academy housed both an elementary school and a high school until 1930 when the elementary school became the "St. Monica Parish Elementary School" and was transferred to its present site on Seventh Street.

After five years it became apparent that even more facilities would be needed for the Academy's high school. In the fall of 1935 the Sisters, at the request of then pastor Monsignor Nicholas Conneally, sold the Academy building and consented to staff a parish high school.  Saint Monica High School opened at its present location in September of 1938. Accommodating both boys and girls, the school's faculty consisted of five sisters and two priests with the first graduating class numbering twenty: seventeen girls and three boys.

At the new location the school grew rapidly and both additional facilities and faculty were needed. The Brothers of Mary came in to teach the boys from 1946 to 1948, at which time the Brothers of St. Patrick took over this job, arriving from Ireland and establishing their first house in the United States. The sisters retained instruction of the girls.

Facilities were expanded in May of 1956 when, under the direction of Msgr. Raymond O'Flagherty, ground was broken for the new Lincoln Boulevard building which was to house the Boys' Department. The Girls' Department would remain in today's West Wing.

In the fall of 1968, for the first time since 1946, classroom instruction became "co-ed". Then in 1970 the two faculties, student bodies and administrations merged under the leadership of Sister Michaeline Mary, SNJM. In June of 1977 the Brothers of St. Patrick decided they could no longer help staff the school, and departed.

Today, more than ninety years after the Sisters of the Holy Names arrival in 1899, their educational ministry continues at Saint Monica High School. Fulfilling the needs of Catholic students of the Santa Monica Bay area, St. Monica's stands as a monument to the struggles and vision of the many religious and priests, and lay women and men who are dedicated to the Christian instruction of youth.