[11][12] Prior to the 2010 realignment, the school participated in the Sussex County Interscholastic League until the SCIL was dissolved in 2009.

[14] The football team competes in the National Blue 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.

[17] Hopatcong High School maintains a variety of boys' and girls' interscholastic sports teams including cross country, soccer, cheerleading, wrestling, basketball, bowling, golf, track and field, softball, baseball and tennis.

These co-op programs operate under agreements scheduled to expire at the end of the 2023–24 school year.

[21] The 2001 team finished the season with a 10-2 record, coming back from a 21-point deficit to defeat Mahwah High School in the North I Group II championship game by a score of 36-35 on a field goal scored with seconds left on the clock.