The Harry W. Mazal Holocaust Collection is the life work of Harry W. Mazal (1937 - 2011), a businessman from Mexico City, who made his home in San Antonio, Texas. With the help of numerous volunteers, Mazal dedicated his life, time, and financial resources to creating a vast repository committed to commemorating the victims of the Holocaust around the world. His goal was to promote scholarly research and human understanding grounded in Holocaust studies while also fighting Holocaust denial, anti-Semitism, and bigotry. As a result, Mazal became an internationally recognized Holocaust collector and researcher.

A significant U.S. collection outside of the Holocaust museums in New York and Washington D.C., the Harry W. Mazal Holocaust Collection is comprised of more than 20,000 books and 500,000 documents, pamphlets, photographs, and other materials, including original transcripts of the Nuremburg trials. It was acquired by the University of Colorado Boulder in January 2014. 

Documenting the tragedy of European Jews before they, their relatives and descendants arrived in America, this collection anchors the Innovations in Jewish Life Collections and makes the University of Colorado Boulder one of the only places in the world to track the Jewish-American experience from the time of the Holocaust through the resurgence of American Judaism in the post World War II period to the vitality of Jewish-American life today.