Greendale High School is a four-year public high school in Greendale, Wisconsin, a suburb of Milwaukee.

Part of the Greendale School District, it serves students in grades 9 through 12.

The Greendale High School marching band has been the Class AA State Champion for 18 consecutive years, from 2005 to 2023,[3][4] and was selected to participate in the 2016 Macy's Thanksgiving Day Parade in New York City[5] as well as the 2020 Tournament of Roses Parade in Pasadena, CA.

[6] The marching band attended the 2023 Macy's Thanksgiving Day Parade[7]