The Red Brick School operated as the sole official school building in Oswego for the next 60 years until the arrival of Caterpillar and Western Electric, who built factories north of Downtown Oswego, near Montgomery, Illinois.

In the early 60s, the village bought farmland along the eastern side of Route 71 (Illinois), and began constructing a new high school.

In the 2000s, the auditorium was dedicated to Dave and Donna Barnes, longtime Oswego drama teachers.

The most recent addition to Oswego High School was in 2013, in which a new wing was built on the northeastern face of the building.

In 2019, Oswego had an average SAT score of 515.4 for math and 515.3 for ELA,[3] and graduated 96.4% of its senior class.

Oswego High School also boasts an active Student Council, a member of the IASC, and National Honors Society.

[10] The school sponsors interscholastic teams for young men and women in basketball, cross country, soccer, swimming & diving, tennis, track & field, and volleyball.

"[12] The following teams have won their respective IHSA sponsored state championship tournaments or meets:[13]