Julidae is a family of millipedes in the order Julida, containing more than 600 species in around 20 genera. Its members are largely confined to the Western Palaearctic, with only a few species extending into the Oriental and Afrotropical ecozones. They are united by a characteristic form of the mouthparts, and are classified in the superfamily Juloidea of the order Julida, alongside the families Trichoblaniulidae, Rhopaloiulidae and Trichonemasomatidae.