[31] The boys' tennis team won the Group III state championship in 1973 (defeating Princeton High School in the tournament final) and 1979 (vs.

[32] The 1973 team finished the season with a 22–3 record, which included defeating Princeton 4–1 in the tournament final for the Group III title.

[33] In 1997, the boys' tennis team went undefeated at 15–0 to claim the NBIL league championship, under head coach Dan Moses.

[37] The 1979 team finished the season with a record of 25–2 after winning the Group II title defeating Bridgeton by a score of 3–2 in the championship game.

[38] The team won the 2016 Group II title with a 9–3 win in the tournament's final game against Arthur L. Johnson High School.

[41] In 2007, the field hockey team won the North I, Group III state sectional championship with a 19–0 win over West Morris Central High School in the tournament final.

[44] The 2019 team won the Group II title, defeating five-time defending champion by 4–1 at Mercer County Park in the final match of the tournament.

[46] The baseball team won the Group III state championship in 1999 vs. Middletown High School South in the playoff final.

[50] The girls took the title again in 2003, over cross-district rival Northern Valley Regional High School at Old Tappan.

[55] The boys' basketball team won the 2004 North I, Group III title, edging Teaneck High School, 53–50.

[61] The Vocal Department includes a Freshman Chorus, Sophomore Women's Chorale, and Concert Choir.

There are also three extracurricular choirs, Men's Choir, Norsemen Notes, and Bel Canto (a select women's ensemble),[62] The department has also won many awards, all groups taking excellent or superior in their last music competition in Williamsburg, VA, competing against groups from all around America and Canada.

[citation needed] Northern Valley Demarest additionally presents a Fall Play and Spring Musical annually.