The school's student body was 49.4% (449) White, 19.3% (175) Hispanic, 12.6% (114) Black, 11.7% (106) Asian, 6.5% (59) two or more races and 0.6% (5) Native Hawaiian / Pacific Islander.

As a school for young men, Saint Peter's opened in September 1878 with seventy-one students in the Preparatory department.

Mulry Hall, on the corner of Grand and Warren Streets, was built around the turn of the century as a local social club, before being acquired by the school.

In 1918 Jesuit Superiors decided to close the college division in order to focus more attention on other Universities in the Northeast.

[22] In front of a crowd of 2,000 at the Dillon Gymnasium at Princeton University, the 1956 team won its sixth consecutive Parochial A state title with a 65–48 win against New Brunswick's St. Peter in the championship game.

[27] In 1994, the Saint Peter's Prep football team finished the season with an 11–0 record was ranked 6th in the nation by USA Today after upsetting top-ranked Bergen Catholic High School with a 26–24 win in the Non-Public Group IV championship game at Giants Stadium.

[28][29] The team won the 2005 Non-Public Group IV state championship defeating Don Bosco Prep 22–15.

[30] Saint Peters won the Non-Public Group IV championship in 2014, with a win over Paramus Catholic High School.

[31] The team won the 2019 Non-Public Group IV title at MetLife Stadium with a 21–14 win against Don Bosco Preparatory High School.

[34] This victory advanced Prep to its third state sectional championship game in three years, all of which have been against Don Bosco Preparatory High School.

On December 2, 2007, the Marauders played Don Bosco Prep again, and lost 42–14 in the Non-Public, Group IV sectional championship game.

The team won the 2007 Boys Volleyball - North state sectional championship over Bayonne High School (25-17, 25–20).

[37] The team moved on to play for the NJSIAA overall state championship on June 8, 2007, against East Brunswick High School,[38] falling 25–21, 25–22.

[39] The Prep basketball team won the 2008 Hudson County Coviello Division Championship by defeating #2 seeded Union Hill by a score of 48–47.

The team also wore sweatshirts printed with the number 20.67, the time that the official score board malfunctioned to in the 50 freestyle on B.J.

[49] The soccer team won the Hudson County Tournament championships in 1976-1978, 1992-1994, 2001, 2005, 2011-2013, 2019 (defeating Kearny High School by a score of 2-1 in the finals) and[50] 2023 (2-1 vs.

This program was continued in August 2008 as Prep sent 16 students and four faculty members to Covington, Louisiana to work with Habitat for Humanity.

Ten rising juniors and seniors, along with two faculty members, traveled to the Working Boys' Center in Quito, Ecuador.

[58] Prep also sends a delegation annually to Fort Moore, Georgia, to protest the Western Hemisphere Institute for Security Cooperation (WHINSEC, formerly the School of the Americas - SOA), which was implicated in the training of mainly Latin American military officers who later committed human rights violations in their home country, including the murder of six Jesuits in El Salvador.