Medieval book ornament is a rapidly developing field of research. In the last decade, the various materials and techniques used to decorate medieval books, their different spaces and textures, their sensory qualities and semantics, and their significance in ritual or other performative contexts have reignited the interest of all disciplines concerned with the medieval book as a material object. Nevertheless, a comprehensive overview of the entire field is lacking. The Handbook of Medieval Book Ornament, creates a reference work, for both students and specialists, discussing the most important terms, topics, and currently discussed concepts related to ornament (in the broadest Middle Latin sense of "ornatus") in medieval book cultures. The focus is on book cultures in the Latin speaking world of Europe from 700 to 1500, including perspectives on Jewish, Islamic, Byzantine and vernacular book cultures and transcultural phenomena. It consists of 200 articles arranged in general themes such as Materials and Techniques, Topology, Sensory Effects, Usage and Pragmatics, Script, and Iconicity. All articles are written by the most renowned experts in the field and include a brief research bibliography, making the handbook an indispensable reference for anyone studying medieval books.