The Saint Joseph Regional High School Green Knights participate in the United Division of the
Big North Conference, a super conference composed of public and private high schools in Bergen and
Passaic counties that was established as part of a realignment of sports leagues in Northern New Jersey and operates under the supervision of the
New Jersey State Interscholastic Athletic Association. The school had temporarily competed in the
North Jersey Tri-County Conference in 2009–10, which was set up to operate on an interim basis while new conferences were established. Until the NJSIAA's 2009 realignment, the school had participated in Division C of the
Northern New Jersey Interscholastic League, which included high schools located in Bergen,
Essex and Passaic counties, and was separated into three divisions based on NJSIAA size classification. With 772 students in grades 10-12, the school was classified by the NJSIAA for the 2019–20 school year as Non-Public A for most athletic competition purposes, which included schools with an enrollment of 381 to 1,454 students in that grade range (equivalent to Group II for public schools). The football team competes in the United Red division of the
North Jersey Super Football Conference, which includes 112 schools competing in 20 divisions, making it the nation's biggest football-only high school sports league. The school was classified by the NJSIAA as Non-Public Group A (equivalent to Group III/IV/V for public schools) for football for 2024–2026, which included schools with 738 to 1,404 students. The Green Knights have achieved league, county and state titles in
football,
baseball,
basketball,
wrestling,
golf,
ice hockey, and winter and spring
track and field athletics in the last two decades. The Green Knights' rivals include
Bergen Catholic High School,
Don Bosco Preparatory High School and
Paramus Catholic High School. ;Fall sports SJR varsity fall sports include football, cross country, and soccer. Long considered a regional powerhouse, SJR football has grown to become one of the best high school football programs in the country. The football team won the NJSIAA state sectional championships 1987 and 1988 (Non-Public A North), 1995 and 1996 (Non-Public Group III), 1997 (Non-Public Group IV), 1999–2005, 2008, 2009, 2011–2013 and 2016 (Non-Public Group III), and 2018 (Non-Public Group IV). The SJR varsity football team had a streak of seven Non-Public Group III titles through the 2005 season, a run ended with a 35-28 loss to
Holy Cross High School on a touchdown scored in the final minute of the first round of the 2006 playoffs. The football team has also had its share of national rankings by
USA Today, including #8 in 1995, #11 in 1997, #7 in 1999, and #23 in 2004. SJR has also been ranked #1 in the state in 1995, 1997, and 1999. Other teams have been listed in the nation's top 25 rankings during various parts of the year. SJR was ranked No. 11 in the nation in the final High School Football America Top 25 in 2013. In 2015, the team finished No. 19 nationally in the High School Football America Top 50. SJR has received
The Star-Ledger Trophy in 1995, 1997, and 1999, 2012 and 2013, recognizing the team as the #1 football team in New Jersey. A 7-0 win by the 1987 team against
Bergen Catholic High School in the playoff finals gave the team the Parochial A North state sectional title and a 9-2 record for the season. The 1988 team finished the season with a 10-1 record after winning the Non-Public A North sectional title after a 29-18 victory against
Delbarton School in the championship game. A 32-26 win in the 1995 Parochial Group III championship game at
Giants Stadium against
DePaul Catholic High School gave the team an 11-0 record for the season. The team won the 2000 Parochial Group III title in 2000 with a 54-29 win against
Pope John XXIII Regional High School in the finals. The 2001 team won the Parochial Group III title with a 17-9 victory in the tournament final against
Immaculata High School. The 2008 team finished with an 11–1 record and won against Immaculate by a score of 27–6 in the Non-Public Group III state championship game. The 2009 varsity football team defeated Immaculata again in the state championship 14–0. Saint Joe's beat
Delbarton School 45–22 in the 2011 Non-Public Group III title game played at
Kean University to earn its 15th state championship title. In 2013, the Green Knights defeated Pope John XXIII, 62–14; it was the fifth in sixth seasons for SJR. In 2016, the program won its 18th state title, winning the Non-Public Group III state sectional championship by a score of 26–17 against
DePaul Catholic High School in the tournament final. The team won the Non-Public Group IV title, the program's first in Group IV, with a 13-0 win against
Bergen Catholic High School. The rivalry with Don Bosco was listed at 15th on
NJ.com's 2017 list "Ranking the 31 fiercest rivalries in N.J. HS football". Don Bosco leads the rivalry with a 30–23 overall record as of 2017, which includes periods in the 1990s and 2010s when the two schools played each other on Thanksgiving. The school's rivalry with Bergen Catholic was listed at 14th, with Bergen Catholic leading with a 31–17 overall record. ;Winter sports SJR offers five varsity winter sports: basketball, bowling, ice hockey, wrestling, and winter track. The SJR basketball team has won a sectional championship; three county championships, most recently in 2005; and five league championships, most recently in 2005, 2007, and in 2009, where they beat
Teaneck High School by a score of 63–50, less than 48 hours after losing to them in the County Jamboree finals 55–53 and ended their season with a record of 16–2 in the NNJIL. In 2005, the SJR basketball team were state finalists, but lost to
Seton Hall Preparatory School 63–54 in the Non-Public North A state sectional tournament. SJR wrestling has been a long dominant force in northern New Jersey and was inducted into the New Jersey Wrestling Hall of Fame in 2005. The team won the Parochial A North state sectional title in 1986, 1988, 1993, 1997, 1998, 1999, 2023, 2024, and 2025, and the Parochial B North title in 1996. The team won the Parochial A state championship in 1993, 1997, 1998, 2023, and 2025, and the Parochial B title in 1996. The ice hockey team was the state champion in 1984, 1985 and 1991, and won the Gordon Cup in 1986, 1990 and 1992. In 2010, SJR hockey, who entered the NJTCC Cup as the lowest seed, upset top-seeded
Passaic Valley High School and
DePaul en route to the championship on February 28. In 2011, the Green Knight Hockey team defeated Hackensack in the first round 6–3, and then defeated
Ramapo High School by a score of 2-1 before losing 2–0 to second-seeded
Wayne Valley High School in the finals. In the winter of 2013, the SJR Ice Hockey team won their fourth league championship appearance in a row. In 2015, the team reached the state quarterfinals after upsetting the #2 ranked
Don Bosco Preparatory High School in the Round of 32. The Green Knight Hockey Team reached the state quarterfinals once again in 2016, losing to
Pope John XXIII Regional High School in overtime. The team will rejoin the Gordon Conference after spending nearly two decades in the Big North Conference. In 2025, the team won their first Bergen County championship after defeating
Don Bosco Preparatory High School by a score of 2–0 in the tournament final. That year they were ranked the #3 team in the state of New Jersey rankings by NJ.com making the highest ranking ever in school history. ;Spring sports SJR offers five varsity spring sports including baseball, golf, lacrosse, tennis, and track and field. The tennis team won the Non-Public North state championship in 1970 (against runner-up
Seton Hall Preparatory School in the final match of the tournament), 1971 (vs.
Christian Brothers Academy) and 1972 (vs.
Mater Dei High School). The baseball team won the Non-Public A state championship in 1993 (defeating
Notre Dame High School in the tournament finals), 1998 (vs.
Eustace Preparatory School) 2004 (vs.
Holy Cross Academy) and 2021 (vs.
St. Augustine Preparatory School). SJR baseball won the NNJIL championship twelve times: in 1984, 1986, 1988, 1992, 1995, 1998-2003, and 2005, and won the county tournament in 1984, 1986, 1988, 1998, 2002, 2003, 2005, 2009, 2013, 2016, and 2024. The 1998 team won the Group A title with 2-1 win against Bishop Eustace in the championship game. The 2009 SJR varsity squad won the county tournament by defeating
Ramapo High School 10–0. The 2009 squad was also a state finalist after a 7–6 victory over nationally ranked
Don Bosco Preparatory High School, but lost to
Delbarton School 4–3. Despite the loss, the team was ranked #5 in the state, and #1 in the county. SJR baseball has also had its share of state and national rankings by
USA Today, achieving #1 in Northern New Jersey in 2002, 2003, 2005 and 2009, #1 in New Jersey in 2005, #10 in the country in 1998, #1 in the east in 1998, #9 in the east in 2004, and is currently ranked #6 in the east in the 2009 season. St. Joe's has had a long-lasting rivalry in baseball with Don Bosco Prep. The spring / outdoor track team won the Non-Public A state championship in 1968 and 1969. ==Theater program==