A variety of magical creatures are depicted in the fictional universe of Harry Potter, which is drawn from various types of media. Magical creatures appear in the Harry Potter novels and their film adaptations, in the Fantastic Beasts film series, in other books by J. K. Rowling, and on the website of the Wizarding World media franchise. In 2001, Rowling released Fantastic Beasts and Where to Find Them, which serves as a guidebook to the creatures described in the fictional universe. Some of these creatures were invented by Rowling. Others are derived from sources such as Greek mythology, English and Celtic folklore, and the works of Roman historians.

In the Harry Potter universe, Magizoology is the study of magical creatures. There are magizoologists who work in the Ministry of Magic, particularly in the department for the Regulation and Control of Magical Creatures. One notable magizoologist is Newt Scamander, who is the author of the in-universe book Fantastic Beasts and Where to Find Them. He is the protagonist of the Fantastic Beasts series of films, which serve as prequels to the Harry Potter series.