The school and several students were featured in the PBS program Frontline in 2008 for an episode related to a generation growing up with the internet.

Instead of midterm exams, students must complete alternate assessment projects, a move strongly supported by co-principal Michael LaSusa and backed by the School District of the Chathams.

[9] Currently, most classes have three more heavily weighted exams or assignments at the end of each third of the school year, although the student transcripts continue to report quarterly.

[19] The school was ranked 183rd in the nation and 14th in New Jersey on the list of "America's Best High Schools 2012" prepared by The Daily Beast / Newsweek, with rankings based primarily on graduation rate, matriculation rate for college and number of Advanced Placement / International Baccalaureate courses taken per student, with lesser factors based on average scores on the SAT / ACT, average AP/IB scores and the number of AP/IB courses available to students.

In past years the Theater Department has put on Macbeth, The Laramie Project, The Crucible, The Adding Machine, You Can't Take It with You, A Midsummer Night's Dream, Scapino, Our Town, Metamorphoses & Look Homeward, Angel.

As for musicals the High School has presented Les Miserables, The Wizard of Oz, The Pajama Game, High School Musical, How to Succeed in Business Without Really Trying, Grease, Guys and Dolls, The Drowsy Chaperone, Legally Blonde, Anything Goes, Once Upon a Mattress, Shrek and The Addams Family Fiddler on the Roof and The Hunchback of Notre Dame.

[36] The 1976 team finished the season with a 17–2 record after winning the Group I state title by defeating Holmdel 3–2 in the playoff finals.

[37] The girls' field hockey team won the North II Group I state sectional championship in 1976-1980 and from 1983 to 1987.

[38] The football team won the North II Group I state sectional championship in 1984, defeating New Providence High School by a score of 20–14 in the tournament final.

[42] The 2010 team advanced to the Group III state championship, where they fell to Holmdel High School by a score of 2–1.

[48] In November 2013, the boys cross country team won the North II Group III sectional title by one point by beating their rivals and defending champion, Morristown.

[49] In 2014, The Cougars won the Morris County championship for the first time since 2006, captured the Northwest Jersey Athletic Conference Large-Schools team title for the first time ever, finished second at the NJSIAA North II Group III championships, third at the overall Group III meet and 13th at the Meet of Champions.

[50] The girls' soccer team won the 2004 Group II NJSIAA state championship, defeating Cinnaminson High School in the finals in double overtime by a score of 1–0.

[56] The 2008 girls' lacrosse team won the triple crown by capturing the conference, county, and Group I state championships while being ranked the no.

[58] Chatham was named Golf Team of the Year by the Daily Record and was ranked fifth in the state of by The Star-Ledger by virtue of their overall finish at the Tournament of Champions event held at Beacon Hill Country Club in Atlantic Highlands.

[63] The 2014 girls' swim team won its fourth consecutive Public B state title, finishing the season with a 15–0 record.

[66] The 2022 boys swim team defeated Princeton High School by a score of 97-73 in the finals to win the program's first-ever Public B state title and finish the season with a record of 16-0.