The Hillsborough High School Raiders competes in the
Skyland Conference, which includes public and private high schools covering
Hunterdon, Somerset and
Warren counties in west
Central Jersey, operating under the supervision of the
New Jersey State Interscholastic Athletic Association (NJSIAA). With 1,723 students in grades 10-12, the school was classified by the NJSIAA for the 2019–20 school year as Group IV for most athletic competition purposes, which included schools with an enrollment of 1,060 to 5,049 students in that grade range. The football team competes in Division 5B of the
Big Central Football Conference, which includes 60 public and private high schools in Hunterdon,
Middlesex, Somerset,
Union and Warren counties, which are broken down into 10 divisions by size and location. The school was classified by the NJSIAA as Group V South for football for 2024–2026, which included schools with 1,333 to 2,324 students. The girls' basketball team won the Group IV State Championship in 2025 defeating West Orange 55-52 and finishing the season with a 26-6 record and ranked #4 in the state. The previous season they won the 2024 North Jersey Section 2 Group IV Sectional Championship by defeating Elizabeth 59-46. The field hockey team won the Central Jersey Group III state sectional title in 1977-1979 and 1981-1983; the team was Group III co-champion in 1983 with
Montville Township High School. The girls' soccer team was Group III co-champion in 1992 with
Northern Highlands Regional High School. The football team won the South Jersey Group 5 regional championship in 2021 defeating Kingsway 28-7. This was a transition year where previously the football season ended with the sectional championships. For the 2021 season, the football calendar ended with group champions for South Jersey and North Jersey. For 2022 and later, the football seasons progressed to crown overall group champions for the entire state. The football team won the Central Jersey Group III state sectional championship in 1980 and the Central Jersey Group IV title in 2000. The 2000 team held off a late comeback by
Sayreville War Memorial High School to win the Central Jersey Group IV title by a score of 16-13 in the playoff finals. The baseball team won the Group IV state championship in 2005, finishing the season with a 21-5 record after defeating
Watchung Hills Regional High School by a score of 5-0 in the tournament final. In 2005, the boys' baseball team won the Somerset County Championship, the Central Jersey Group IV sectional final and the Group IV finals. The team has won the Somerset County Tournament in 1977, 1979, 2005, 2012, 2014 and 2015; the six titles (through 2018) are tied for second-most in the tournament's history since it was established in 1973. The boys swimming team won the Public A state championship in 2005. The boys' swimming team won the 2007 Central - A state championship with a 103-67 win against
Montgomery High School. In 2009, David Wilson broke his own school record (21.05) for the 50 freestyle to win the individual state championship and claim the title of "fastest man in the state." At the Meet of Champions, Wilson earned All-American status for the butterfly 200 medley relay. The ice hockey team won the Monsignor Kelly Cup in 2006. The boys' track team was Group IV indoor relay co-champion in 2008 with
Trenton Central High School. In 2008, Mary Kate Lynch was honored at the NJSIAA Annual Scholar Athlete Luncheon representing Hillsborough High School. In 2009, Steven Wu won the singles title at the Somerset County Boys Tennis Tournament. In 2022, the team was the Somerset County Tournament co-champion along with
Pingry School. In 2023, the team won the Group IV sectional title, defeating
South Brunswick High School 3-2 in the final. The rugby team participates in a competitive league with schools such as
Delbarton School, Xavier High School, and
Darien High School. The girls' cross country team won the Group IV state championship from 2010-2012 and 2014 and won the Meet of Champions in 2009 and 2010. In 2009, the team won the overall state championship by defeating
Randolph High School by a single point, 78-79, to win the Meet of Champions in Holmdel. In 2010, the team won the Group IV state title and repeated as the overall state champion by winning the Meet of Champions by a 95-111 margin over Voorhees, earning the team recognition by
The Star-Ledger as its team of the year. The girls' indoor / winter track team won the Group I state championship in 2020. ==Graduation requirements==