Ernest Flagg was an American architect in the Beaux-Arts style. He was also an advocate for urban reform and architecture's social responsibility.

Beaux-Arts architecture was the academic architectural style taught at the École des Beaux-Arts in Paris, particularly from the 1830s to the end of the 19th century. It drew upon the principles of French neoclassicism, but also incorporated Renaissance and Baroque elements, and used modern materials, such as iron and glass, and later, steel. It was an important style and enormous influence in Europe and the Americas through the end of the 19th century, and into the 20th, particularly for the institutional buildings.