Founded in 1920 to educate young women, the need for a Catholic high school in the Fitchburg area was recognized by Bishop Thomas Daniel Beaven, and then materialized during the pastorate of Monsignor James J. Donnelly.

The religious institute, founded by Nano Nagle, called the Presentation Sisters were tasked with beginning the school.

[1] In 1925, Donnelly purchased the Page Estate in Fitchburg, which became a convent for the Sisters, and in July 1926, construction of a nearby building would become the St. Bernard's High School campus.

"[2] In 1964, a quarter-mile running track was added, as well as an additional building wing containing a cafeteria, chapel, classrooms, laboratories, library, and offices.

St. Bernard's High School won a bid to privatize and operate independently with a board of trustees, as of 2020.