The school opened at its current location in January 1977, after multiple issues with subcontractors led to several delays from the original planned opening in September at the start of the school year. Constructed at a cost of $4.5 million and offering 50% more space than its predecessor, the building served 650 students, including 140 from Edgewater.
Awards, recognition and rankings
In the 2011 "Ranking America's High Schools" issue by The Washington Post, the school was ranked 14th in New Jersey and 657th nationwide. The school was the 94th-ranked public high school in New Jersey out of 339 schools statewide in New Jersey Monthly magazine's September 2014 cover story on the state's "Top Public High Schools", using a new ranking methodology. The school had been ranked 52nd in the state of 328 schools in 2012, after being ranked 49th in 2010 out of 322 schools listed. The magazine ranked the school 51st in 2008 out of 316 schools. The school was ranked 67th in the magazine's September 2006 issue, which included 316 schools across the state. Schooldigger.com ranked the school as 174th out of 376 public high schools statewide in its 2010 rankings which were based on the combined percentage of students classified as proficient or above proficient on the language arts literacy and mathematics components of the High School Proficiency Assessment.
Extracurricular activities
In 1957, the school's chess team was the New Jersey high school team champion, winning the Father Casimir J. Finley Trophy.
Academic Competition
Leonia has had an active quiz bowl team for decades. In April 2017, Leonia won the Junior Varsity National Championship title for the Small School Division of the National History Bowl, led by Nathan Finn, who was the 2016 Junior Varsity New Jersey History Bee State Champion.
Athletics
The Leonia High School Lions participate in the North Jersey Interscholastic Conference, which consists of public and private schools located in Bergen County, Passaic County and Hudson County, following a reorganization of sports leagues in Northern New Jersey by the New Jersey State Interscholastic Athletic Association. Prior to the realignment that took effect in the fall of 2010, Leonia was a member of the Bergen County Scholastic League Olympic Division. With 508 students in grades 10–12, the school was classified by the NJSIAA for the 2015–16 school year as North II, Group II for most athletic competition purposes, which included schools with an enrollment of 508 to 770 students in that grade range. The school operates as the host school / lead agency for joint girls' soccer and boys' and girls' swimming programs with Palisades Park High School, under an agreement that expires at the end of the 2018–19 school year; in turn, Palisades Park High School is the host school / lead agency for a cooperative football program with Leonia that expires at the end of the 2018–19 school year. The school has fielded only one team to win a New Jersey State Interscholastic Athletic Association statewide championship, the 1967 varsity basketball team, which defeated Burlington Township High School in the Group I tournament final. Leonia football, which is a co-op program with Palisades Park High School, became the first cooperative program to have reached a finals game in state history when the team made the North Jersey II Group III state championship game in 2012, falling to Summit High School by a 30–0 final score. The team finished 9–3 which was the most wins in Leonia school history, and Head Coach David Schuman was awarded NJIC coach of the year and The Record ranked the team 12 in North Jersey.
Administration
The principal is Charles Kalender. His administration team includes the vice principal and athletic director.
