This literary analysis thesis determines the relationship between twin characterization in Victorian novels and contemporary literature. Using Robert Louis Stevenson’s Strange Case of Dr. Jekyll and Mr. Hyde and Lewis Carroll’s Through the Looking-glass as foundational works for twin characterization with the Freudian definition of doubles as uncanny, this thesis analyzes the following twin tropes: the trickster twins, twins separated into binaries of “good” or “whole” and “damaged” or “evil,” male twins where one dies and the other marries the woman they both love, and female twins associated with shared supernatural appearance and abilities. These tropes are identified in Victorian works including Sarah Grand’s The Heavenly Twins and Wilkie Collins’ Poor Miss Finch, then demonstrated in contemporary sources including Ian McEwan’s novel Atonement, Kim Edwards’s novel The Memory-Keeper’s Daughter, J. K. Rowling’s Harry Potter series, and Stanley Kubrick’s film The Shining. Ultimately, this thesis analyzes these tropes of twin characterization in 19th-century and contemporary literature from a variety of genres to demonstrate how the fin de siècle fears of cultural degradation, explored through duality using the vehicle of twin characters, remain as pervasive influences in today’s literature with similar concerns about individual identity.