Don Bosco Prep was founded on April 3, 1915, with the arrival of the first students, who transferred from Don Bosco Polish Institute in Hawthorne, NY. The Ramsey school, initially known as Don Bosco Institute, was a boarding school for Polish boys taught by Polish Salesian priests. St. John Bosco's educational methodology, employing reason, religion, and kindness to reach the hearts of the young, inspired the Salesian priests and brothers.
Student enrollment rapidly increased, especially with the applications of students from the growing surrounding communities, who wished to attend as day students. During the 1940's, with students attending from a wide geographic area, the athletic teams earned the name "Ironmen", a title awarded first to the illustrious championship Don Bosco Prep Basketball Team of 1944. This name stuck and continues to inspire Don Bosco students as academics, athletes, and men. Immaculata Hall was built in 1954. This building provided many new classrooms, a large cafeteria as well as a spacious gymnasium. The doors were now open to all high school applicants.
Over the years, as the school solidified its reputation in quality Salesian education, De Sales Hall was built in 1969. It provided a beautiful auditorium for theatre and assemblies, extensive classrooms, lecture halls, and science laboratories, as well as administrative offices for the school. By 1972, the last boarding students graduated, and the student body from that time forward was comprised entirely of day students. A generous donation from the Granatell Family allowed the school to build the Charles I. Granatell Athletic Stadium in 1972. Reconstruction of the athletic field with the installation of state-of-the-art FieldTurf, a new track, and the addition of an Alumni Park further improved the Granatell Stadium complex in 2003.
The tens of thousands of Don Bosco Prep alumni, who can be seen in class photos lining the corridors of Immaculata Hall, have gone on to make significant contributions to society in all walks of life.