The Montville High School Mustangs compete in the
Northwest Jersey Athletic Conference, an athletic conference comprised of public and private high schools located in Morris,
Sussex and
Warren counties in Northern New Jersey, that was established following a reorganization of sports leagues in Northern New Jersey by the
New Jersey State Interscholastic Athletic Association (NJSIAA). With 904 students in grades 10–12, the school was classified by the NJSIAA for the 2019–20 school year as Group III for most athletic competition purposes, which included schools with an enrollment of 761 to 1,058 students in that grade range. Montville is assigned to the American Division for most sports. Prior to the NJSIAA's realignment that took effect in the fall of 2009, Montville was a member of the Suburban Division of the
Northern Hills Conference. The football team competes in the Patriot White 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 Group III North for football for 2024–2026, which included schools with 700 to 884 students. The 1978 baseball team finished the season at 16–10 after winning the Group II state championship with a 3–1 win against
South Brunswick High School in the championship game. The 2007 Mustang baseball team defeated
Northern Valley Regional High School at Old Tappan, 9–7, to take the North I Group III section title for the first time since 1989. The team has won the Morris County Tournament three times, tied for the fourth-most in tournament history, winning in 1974, 1980 and 1992. The girls' field hockey team won the North II Group II state sectional championship in 1975 and 1977, and the North II Group III state sectional title in 1980, 1981, 1983 and 1984. The team won the Group III state championship in 1980 (vs.
Ocean Township High School), 1981 (vs.
Camden Catholic High School) and 1983 (as co-champion with
Hillsborough High School). The 1980 team finished the season with a record of 19-1-3 after winning the Group III title with a 3–2 win against Ocean Township in overtime in the tournament final at
Mercer County Park. The girls' lacrosse team won the overall state championship in 1984, defeating
Moorestown Friends School in the tournament final. The girls tennis team won the Group III state championship in 2013, defeating
Princeton High School in the tournament final. The 2013 team beat
Moorestown High School 4–1 in the semifinals and moved on to defeat Princeton 4–1 in the finals. In 2001, the Montville boys' soccer team won the North II, Group II state sectional title with a 2–1 win in the championship game against
Pequannock Township High School in sudden death overtime. In 2009, the Montville boys' soccer team tied
Madison High School 0–0 in the final of the Morris County tournament. The shared title was the first in the program's history. The Mustangs went on to win their third ever sectional title, beating
Northern Highlands Regional High School 2–0 in the final. In 2010, Montville captured the Morris County boys' soccer title outright, winning 1–0 in overtime against
Chatham High School. The Mustangs also repeated as sectional champions, defeating
Wayne Valley High School 5–1 in the section final for their fourth ever title. The girls' track team won the Group I indoor relay state championship in 2002. In 2003, the Montville Mustang football team set school records with nine wins and six shut outs, winning the first round of the state sectionals before losing in the state semi-final game, earning induction into the Montville Township Hall of Fame in 2011. The ice hockey team won the Haas Cup in 2009 and 2018, and won the Halvorsen Cup in 2015. The boys' wrestling team won the North I Group III state sectional title in 2009, 2019 and 2020. The team won the Group III state championship in 2020. The boys' bowling team won the Group III state championship in 2014 and wom the Group II title in 2022. In 2014, Meg Hishmeh was hired as the head coach of the boys' ice hockey team, becoming the first women in the state to serve as hockey coach of a boys' team. == Extracurricular activities ==