Cassie L. Chadwick (10 October 1857 – 10 October 1907) was the most well-known pseudonym used by Canadian con artist Elizabeth Bigley, who defrauded several American banks out of millions of dollars during the late 1800s and early 1900s by claiming to be an illegitimate daughter and heiress of the Scottish-American industrialist Andrew Carnegie. Newspaper accounts of the time described her as one of the greatest con artists in American history. She pulled off the scam in the Gilded Age of American history, during which time women were not allowed to vote or get loans from the banks, leading some historians to refer to her bank heist as one of the greatest in American history.