The Harrison High School Blue Tide participate in the Meadowlands Division of the North Jersey Interscholastic Conference, which is comprised of small-enrollment schools in Bergen, Hudson, Morris and Passaic counties, and was created following a reorganization of sports leagues in Northern New Jersey by the New Jersey State Interscholastic Athletic Association (NJSIAA). Prior to the NJSIAA's 2010 realignment, the school had participated in the Bergen County Scholastic League (BCSL). With 525 students in grades 10-12, the school was classified by the NJSIAA for the 2019–20 school year as Group II for most athletic competition purposes, which included schools with an enrollment of 486 to 758 students in that grade range. The school was classified by the NJSIAA as Group II South for football for 2018–2020.