|Headquarters||1161 Route 130|
Robbinsville, NJ 08691
|425 high schools|
|Affiliations||National Federation of State High School Associations|
The New Jersey State Interscholastic Athletic Association (NJSIAA) is an association of hundreds of New Jersey high schools that regulates high school athletics and holds tournaments and crowns champions in high school sports.
In order for schools to move on to the state championship, they must achieve a winning percentage of .500 or greater by a pre-set date (the "cut-off" date). Football, wrestling and bowling are the only sports where a school may have a .500 record and not qualify for the postseason. For football and wrestling, it is only the best eight schools in each section that move on. This is determined by power points, awarded to each game's winning team and based on the size of the school that is defeated and the score of the game. Winning percentage alone, however, is not sufficient to qualify for the playoffs. If a school's team has too many disqualifications, it is disqualified from the state championship. In bowling the top 2 teams in each division (North I, Group I; North I Group II, etc.) in the State Sectional Tournament, qualify for State Finals.
When a team wins its sectional championship, it is awarded a blue trophy on which is noted the section and the sport. For public schools, the two North Jersey winners face off against one another, while the South and Central teams play each other in the statewide semi-finals. The two winning teams then play each other for the statewide Group championship. For non-public schools, the two section winners compete in the state Non-Public championship; the champion receives a gold trophy.
For some sports, each group's state champion play each other in the Tournament of Champions for the overall state championship and #1 state ranking. For boys, the tournament is offered in basketball, bowling, cross country, golf, lacrosse, tennis, track-indoor, track-outdoor, and volleyball. For girls, the sports are basketball, bowling, cross country, field hockey, lacrosse, tennis, indoor and outdoor track, and volleyball.
In some sports, there are no group championships. In these sports -- all schools, public and non-public alike -- compete for a single state championship. For boys, the sports are fencing and golf. For girls, they are fencing, golf, and gymnastics.
Student athletes may also be state champions. The sports that offer individual state championships are bowling, cross country, fencing, golf, gymnastics, tennis (singles and doubles), swimming, diving, indoor and outdoor track, and wrestling. All of these sports -- except gymnastics (girls only) and wrestling (boys only) -- produce both male and female individual champions.
A proposal introduced by Northern Highlands Regional High School to the NJSIAA executive committee in April 2012 would create a Group V for football that would include the 15 largest schools in each of the four regions. Under the proposal, 160 public schools (up from 128) would be eligible for the playoffs and there would be an additional 28 games played in the sectional tournaments.
On August 11, 2008, the NJSIAA released an official proposal for a realignment of athletic conferences located in Central and North Jersey. The proposal affects over 200 NJSIAA high schools in 31 conference divisions, making it the single largest realignment in state history. The result is six "super" conferences according to geography. A seventh, football-only conference would also be created for teams from two of the new super conferences. Not affected by this move are schools located in Mercer, Monmouth, and Middlesex counties as well as all of South Jersey.
Multiple reasons account for the super conferences realignment. First, the plan was triggered by dissatisfaction with competitive balance between schools, particularly in the football programs in public and non-public schools in the northern part of the state. It would allow schools more flexibility with whom they schedule for such events. Second, new enrollment totals and rates have vastly changed since the conferences were set up 27 years ago, and therefore have not adequately met the needs of all the schools. A final catalyst is the economy; the move would create cheaper overall traveling expenses.
The realignment by the NJSIAA has garnered very mixed reactions among the high schools that it would affect. For instance, Eastside High School, which has traditionally been beaten handily in athletic competition, endorses the move. Meanwhile, Summit High School has enjoyed great success in their conference and sees no need to part ways. Other schools generally share one of these two views.
The realignment, which was started for the 2009-10 school year, may only go into effect for 2-3 years, and if it does not work out well, a reversion to the old conferences is still a possibility.
In 2018, the NJSIAA will become the first state governing body to sanction the use of video replay during high school football's regular season. 
In the 2016-17 season, the NJSIAA featured 283,655 participants, with 57% boys and 43% girls.
The sports with most boys are:
The sports with most girls are: