Classen School of Advanced Studies

Classen School of Advanced Studies (often referred to as Classen SAS, CSAS, or simply Classen, not to be confused with Northwest Classen High School) is a public magnet school serving students in grades 6-12 in Oklahoma City, Oklahoma. The Oklahoma City Public Schools program participates in the IB Diploma Programme and offers fine arts courses as well, offering art, drama, and music classes to any qualifying student.

Classen is known as one of the state's premier high schools in academics, and has been ranked among the top 100 public high schools in America by the Challenge Index, as measured by the number of Advanced Placement, International Baccalaureate and/or Cambridge tests taken by all students at a school in 2007 divided by the number of graduating seniors. The index is published annually in the Washington Post and Newsweek. It was ranked 14 in 2009.

As Classen High School, the basketball team won state championships in 1929, 1934, 1937, 1948, 1950, 1975, and in 1980. In 1995, Classen SAS won the Class B State Championship in Academic Quiz Bowl and in 1996, Classen SAS was the Class 3A State Runner-Up in Academic Quiz Bowl. It is currently a Division 3A school.