Hazelwood West High School began in 1974, with the first graduating class in 1975. Due to overcrowding of Hazelwood Senior High School (now known as Hazelwood Central), students attended classes on split shift in afternoons. The building that would partially become Hazelwood West opened in 1969 as a junior high school, Howdershell Jr. High. A greatly expanded building opened as a six-year facility in the fall of 1975, housing students in grades seven through twelve. In 2002, all district junior high schools were renamed middle schools. In 2005, two new building additions were added, a band room near the main entrance and a three-story classroom wing in the rear of the former middle school section. With the completion of six new middle schools in 2007; Central Middle, North Middle, Northwest Middle, East Middle, Southeast Middle, and West Middle; Hazelwood West was designated solely as a high school.
This includes institutions outside of the city limits of St. Louis which have "St. Louis, MO" postal addresses. Note multiple places with "St. Louis, MO" postal addresses are not in the St. Louis city limits.