O'Fallon Township High School is a public secondary school in O'Fallon, Illinois.

As of 2023, it is the second largest public high school in Illinois by enrollment outside of the Chicago area (Belleville High School-East being the largest).

[3] As stated in the 1962 edition of The Panther, the symbology on O'Fallon Township High School's crest reflects the town's history of farming, industry, and coal mining.

[4] Today, the school's coat of arms/crest can be found in the Smiley Campus's 600 hallway on a bronze plaque gifted by the Class of 1961.

After a short tenure as an assistant principal, longtime teacher Rich Bickel became the principal in 2009, following the retirement of Steve Dirnbeck who served as the school's principal from 2003-2009.