Allison Mansion, also known as Riverdale and Marion College Library, is a historic home located on the campus of Marian University at Indianapolis, Marion County, Indiana. It was built between 1911 and 1914, and is a large two-story, Arts and Crafts style red brick mansion with a red tile roof. The house features a sunken conservatory, porte cochere, and sunken white marble aviary. It was added to the National Register of Historic Places in 1970.