Dorothy Harriet Camille Arnold (July 1, 1885 – disappeared December 12, 1910) was an American socialite and heiress who disappeared under mysterious circumstances in New York City in December 1910. The daughter of Francis R. Arnold, a fine goods importer, Arnold was born and raised in Manhattan in an affluent family. After graduating from Bryn Mawr College, she returned to her family home at 108 East 79th Street and attempted to begin a career as a writer. On December 12, 1910, Arnold left her home to go shopping for a dress and was seen by a cashier as well as a friend on Fifth Avenue. She told the friend that she had planned to walk through Central Park before returning home. That evening, when Arnold failed to return home for dinner, her family grew suspicious.