St. Pius X High School was founded in 1959 to provide a Catholic education for high school students in Jefferson County, Missouri, United States.

The only Catholic high school in Jefferson County, St. Pius X is part of the Roman Catholic Archdiocese of Saint Louis.

102 hours of community service are part of the graduation requirements for each student, along with a capstone project requirement implemented for the class of 2021 and beyond.

St. Pius X principal Karen DeCosty is an alumnus of the school, graduating in 1993.

St. Pius X offers the following MSHSAA sports and activities: