Thornridge High School first opened to the public in 1960 after completing construction of the current building.

It serves the cities/villages of Dolton, Harvey, South Holland, Phoenix, Burnham, Calumet City, and Markham.

[11] The Falcons compete in the Southland Athletic Conference (SAC) as well the state championship series sponsored by the Illinois High School Association (IHSA) which governs most athletic and competitive activities in Illinois.

The school sponsors interscholastic teams for both young men and women in basketball, bowling, cross country, soccer, tennis, and track & field.

Young men compete in baseball, football, swimming and diving and wrestling.