The work is devoted to the study of biblionyms as one of the most important components of onomastics. It examines the biblionymy of Chuvash, Russian and English fiction using the methods of continuous sampling, systematization and classification of material, descriptive-analytical and comparative approaches. At the moment, biblionyms have not been studied enough. At the same time, their study is relevant and significant, since the title can be the key to understanding the text. This work is intended to clarify the interpretation of the term “biblionym”. At the same time, the author examines the functions of biblionyms, their classification, and identifies the place of titles in the system of onomastic terminology of the languages under study, which in the future should contribute to the development of the general theory of onomastics. The author of the work suggests using the term “biblionym” to understand the name of any text. At the same time, from his point of view, there is a need to introduce into onomastic studies such terms as “microbiblionym” for the names of chapters, paragraphs and constituent parts of the text and “macrobiblionim” for the names of collections of texts. By its position, a biblionym is a means of connecting the text with the outside world, in particular with the reader. Based on the biblionym, the reader will be able to form an idea of the content of the text.