Deady Hall is a historic building located in Eugene, Oregon, United States. It was the University of Oregon's first building, and remained the university's only building for almost ten years after its construction. After the university gained other buildings, it was known simply as the "Old Building", but in 1893 it was renamed "Deady Hall" in honor of Matthew Deady, Oregon's first federal judge.
Deady Hall is variously described as simplified Italianate with Second Empire details or simply as Second Empire (though not as elaborate an example as Villard Hall).
This building was listed on National Register of Historic Places in 1972. It and nearby Villard Hall were together designated as one National Historic Landmark in 1977.