The first public high school in Onalaska was founded in January 1890 on a plot of land between Main, King, Fourth and Fifth Streets.

[3] OHS is 71.7% white, 12.6% Asian, 6.1% Hispanic, 6.1% two or more races, 2.4% black, and 0.4% American Indian, and 0.1% Native Hawaiian/Pacific Islander.

[7] They continue to be a major force, ranking 2nd in the nation, winning six grand championships, best band, and best vocals awards in their 2020 season with their show themed after the Netflix TV series The Umbrella Academy.

[8] OHS also hosts its own annual competition, the Onalaska Show Choir Classic, which started in 1987.

[7] It is noted for being one of the toughest competitions in the Midwest and attracts schools from Wisconsin, Minnesota and Iowa.