The Case Study of Vanitas (Japanese: ヴァニタスの手記カルテ, Hepburn: Vanitasu no Karute) is a Japanese manga series written and illustrated by Jun Mochizuki. It has been serialized in Square Enix‘s shōnen manga magazine Monthly Gangan Joker since December 2015. The Case Study of Vanitas is set in 19th century Paris and contains vampire and steampunk thematics. In North America, the manga is published in English by Yen Press. An anime television series adaptation by Bones premiered in July 2021.

During an airship ride to Paris, the vampire Noé Archiviste meets Vanitas, a human claiming to be a doctor for vampires, curing them of the malnomen, which cause vampires to behave predatorily against their will. The book with which he heals, The Book of Vanitas, is connected to the original Vanitas, the Vampire of the Blue Moon, hated by the Vampires of the Red Moon who form traditional vampire society. Noé and Vanitas join forces to heal vampires, but there lurks a threat of some unknown force named Charlatan, which may be responsible for corrupting the sick vampires.