Acorn Hall is an 1853 Victorian Italianate mansion located at 68 Morris Avenue in Morristown, Morris County, New Jersey. It was added to the National Register of Historic Places on April 3, 1973, for its significance in architecture. It serves as the headquarters of the Morris County Historical Society, which operates Acorn Hall as a historic house museum. After inheriting the property, antiwar activist and actress Mary Crane Hone tried for decades to donate the property for historical preservation, finally succeeding in 1971.