English: The Andrew W. Mellon Auditorium (center building) located at 1301 Constitution Avenue, NW in the Federal Triangle area of Washington, D.C. Originally known as the Treasury Department Auditorium, the building was designed by Arthur Brown, Jr. and constructed between 1928–1934. A sculpture by Edgar Walter, named Columbia, is within the pediment.

In addition to the 2500-seat assembly hall, the building contains several offices and small meeting rooms. The buildings on either side of the auditorium are part of the William J. Clinton Federal Building, which houses headquarters offices for the Environmental Protection Agency.

Notable events which have taken place at the auditorium include Franklin D. Roosevelt's initiation of the Selective Service System on October 29, 1940, and the signing of the North Atlantic Treaty on April 4, 1949. The auditorium is a contributing property to the Pennsylvania Avenue National Historic Site.