[10] As the borough population grew, it was decided to construct a new school building at the corner of West Grant Avenue and Locust Street.

In 1919, the high school moved to a new building formerly occupied by the Hercules Munitions Company and located at the corner of West Clay Avenue and Locust Street.

However, industrial arts and physical education classes continued to meet in the previous school building.

[12] During this time, students from the surrounding municipalities of Garwood, Kenilworth, and Springfield attended Roselle Park High School on a tuition basis.

[16] The Roselle Park High School Panthers[2] compete in the Union County Interscholastic Athletic Conference, which is comprised of public and private high schools in Union County and was established after a reorganization of sports leagues in Northern New Jersey by the New Jersey State Interscholastic Athletic Association (NJSIAA).

[19] The football team competes in Division A of the Big Central Football Conference, which includes 60 public and private high schools in Hunterdon, Middlesex, Somerset, Union and Warren counties, which are broken down into 10 divisions by size and location.

[23] The 1972 team finished the season with a 19-5 record after winning the Group I title with a 9-6 victory in the championship game.

[25] An 11-0 season in 1992 culminated with a 27-6 win against Butler High School in the North II Group I state sectional championship game.

[26] The 1993 finished the season with an 11-0 record and won its second consecutive North II Group I title with a 10-7 victory on a field goal in overtime against Summit High School in the championship game.

[34] The team won the 2018 Group I title with a 4-3 win in extra innings against Gloucester City in the championship game before losing to eventual-champion Steinert High School in the quarterfinal round of the Tournament of Champions to finish the season with a 27-3 record.