[6][7] Starting in 2009 and completed in 2011, Glen Rock High School underwent a $45.3 million renovation project that included a new science wing, a creative arts department, and system updates.

[12] Glen Rock was ranked 30th in New Jersey and 287th nationwide in Newsweek magazine's 2012 issue of "America's Best High Schools.

[32][33] Because the NJIC does not offer competition in these sports, Glen Rock is a member of the Big North Conference for hockey and competes in lacrosse-specific leagues for both boys' and girls' lacrosse.

[38] Down 21–7 at the half, the 1988 team pulled ahead to defeat Park Ridge High School by a score of 22–21 to win the North I Group I championship game.

[40] The team won the 2001 North I, Group I state sectional championship with a 22–14 win in double overtime in the tournament final against Cresskill High School.

[44] The 1999 team finished the season with a 21-1-1 record after defeating Rumson-Fair Haven Regional High School by a score of 2–0 to win the Group I state championship.

[45] In 2012, the girls soccer team won the North I, Group II state sectional final with a 1–0 win against Ramsey High School.

[50] The boys tennis team won the Group I state title in 2000, defeating Mountain Lakes High School in the finals.

[52] The girls tennis team took the North I, Group I sectional title in 1999 with a 4–1 win vs. Henry P. Becton Regional High School in the tournament finals.

[55] The ice hockey team won the Public B state championship in 2017 with an 8–1 win in the tournament finals at the Mennen Arena against Wall High School to run their season record to 22-3-3.