The school opened in a building on the grounds of St. Stanislaus Church in Lansdale in September of 1949 with only a freshman class. It was named Little Flower Catholic High School, after its patron Saint, St. Theresa of Lisieux. Each succeeding year, another class/year was added and in 1953, commencement exercises were held for the the first graduating class of 33 students. That building is still functioning on the property of St. Stanislaus and today is called Little Flower Hall.
Probably the main, if not the only, driving force to bring about the establishment of the school was Monsignor Joseph Schade, who was the Pastor of St. Stanislaus Parish in Lansdale at that time. He was aided in his efforts by the willingness of the Sisters of St. Francis of Philadelphia who initially staffed the school, with Sister M. Theresa Clare being the first principal (and one of the teachers).